I recently hired a guy to convert the rear brakes on my 82 CJ from
drum to disc. (There was nothing wrong with the drums, I just had
some spare cash burning a hole in my pocket.)

However, after the job was complete, the disc brakes stop the vehicle
MUCH more poorly than the old drums. In fact it's now quite dangerous
to drive. There is now absolutely no resistance in the first 2/3 of
the brake pedal. There is finally some resistance and grab in the
last 1/3 of the pedal, but even mashed all the way to the floor, the
brake pedal only gives me a moderately effective stop. If I get into
a freeway situation requiring quick braking, I will be in very serious
trouble.

I do seem to be able to get more resistance by quickly pumping the
brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
noticeably harder, but it still isn't super great for stopping.

The guy who did the work said that he suspects the problem is the
master cylinder. He claims that the stock master cylinder on CJs is
probably just not high enough capacity to handle the additional
demands of the rear disc brakes, and that I could fix the problem by
upgrading to a higher capacity master cylinder. I don't know nearly
enough about mechanics to know if this is good advice or not
(otherwise I would have done the job myself...) so can anyone here
tell me if this is a reasonable answer? If so, any suggestions on
what master cylinder to use as a replacement? If not, any other
ideas?

The guy who did the work came highly recommended by many local jeepers
and has been popular with local jeep clubs for 20+ years, so I tend to
think it's not just a case of him doing shoddy work or rippig me off.
( He assured me that he topped off the brake fluids, bled the brakes,
and did everything else properly.) Unfortunately I can't take it back
to him since I moved 1100 miles away immediately after this work was
done.

 

I'd tend to think he's right or there's still some air in the lines. I've
had several MCs go out immediately after brake jobs, particularly on older
cars, so it could be a case of that instead of it just being too small. I'd
try having the lines bled again just to be sure, and if that doesn't fix it,
upgrade the MC.

"sm3gurpal" <elambeth@hotmail.com> wrote in message
news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> I recently hired a guy to convert the rear brakes on my 82 CJ from
> drum to disc. (There was nothing wrong with the drums, I just had
> some spare cash burning a hole in my pocket.)
>
> However, after the job was complete, the disc brakes stop the vehicle
> MUCH more poorly than the old drums. In fact it's now quite dangerous
> to drive. There is now absolutely no resistance in the first 2/3 of
> the brake pedal. There is finally some resistance and grab in the
> last 1/3 of the pedal, but even mashed all the way to the floor, the
> brake pedal only gives me a moderately effective stop. If I get into
> a freeway situation requiring quick braking, I will be in very serious
> trouble.
>
> I do seem to be able to get more resistance by quickly pumping the
> brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> noticeably harder, but it still isn't super great for stopping.
>
> The guy who did the work said that he suspects the problem is the
> master cylinder. He claims that the stock master cylinder on CJs is
> probably just not high enough capacity to handle the additional
> demands of the rear disc brakes, and that I could fix the problem by
> upgrading to a higher capacity master cylinder. I don't know nearly
> enough about mechanics to know if this is good advice or not
> (otherwise I would have done the job myself...) so can anyone here
> tell me if this is a reasonable answer? If so, any suggestions on
> what master cylinder to use as a replacement? If not, any other
> ideas?
>
> The guy who did the work came highly recommended by many local jeepers
> and has been popular with local jeep clubs for 20+ years, so I tend to
> think it's not just a case of him doing shoddy work or rippig me off.
> ( He assured me that he topped off the brake fluids, bled the brakes,
> and did everything else properly.) Unfortunately I can't take it back
> to him since I moved 1100 miles away immediately after this work was
> done.

 

I'd tend to think he's right or there's still some air in the lines. I've
had several MCs go out immediately after brake jobs, particularly on older
cars, so it could be a case of that instead of it just being too small. I'd
try having the lines bled again just to be sure, and if that doesn't fix it,
upgrade the MC.

"sm3gurpal" <elambeth@hotmail.com> wrote in message
news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> I recently hired a guy to convert the rear brakes on my 82 CJ from
> drum to disc. (There was nothing wrong with the drums, I just had
> some spare cash burning a hole in my pocket.)
>
> However, after the job was complete, the disc brakes stop the vehicle
> MUCH more poorly than the old drums. In fact it's now quite dangerous
> to drive. There is now absolutely no resistance in the first 2/3 of
> the brake pedal. There is finally some resistance and grab in the
> last 1/3 of the pedal, but even mashed all the way to the floor, the
> brake pedal only gives me a moderately effective stop. If I get into
> a freeway situation requiring quick braking, I will be in very serious
> trouble.
>
> I do seem to be able to get more resistance by quickly pumping the
> brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> noticeably harder, but it still isn't super great for stopping.
>
> The guy who did the work said that he suspects the problem is the
> master cylinder. He claims that the stock master cylinder on CJs is
> probably just not high enough capacity to handle the additional
> demands of the rear disc brakes, and that I could fix the problem by
> upgrading to a higher capacity master cylinder. I don't know nearly
> enough about mechanics to know if this is good advice or not
> (otherwise I would have done the job myself...) so can anyone here
> tell me if this is a reasonable answer? If so, any suggestions on
> what master cylinder to use as a replacement? If not, any other
> ideas?
>
> The guy who did the work came highly recommended by many local jeepers
> and has been popular with local jeep clubs for 20+ years, so I tend to
> think it's not just a case of him doing shoddy work or rippig me off.
> ( He assured me that he topped off the brake fluids, bled the brakes,
> and did everything else properly.) Unfortunately I can't take it back
> to him since I moved 1100 miles away immediately after this work was
> done.

 

I'd tend to think he's right or there's still some air in the lines. I've
had several MCs go out immediately after brake jobs, particularly on older
cars, so it could be a case of that instead of it just being too small. I'd
try having the lines bled again just to be sure, and if that doesn't fix it,
upgrade the MC.

"sm3gurpal" <elambeth@hotmail.com> wrote in message
news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> I recently hired a guy to convert the rear brakes on my 82 CJ from
> drum to disc. (There was nothing wrong with the drums, I just had
> some spare cash burning a hole in my pocket.)
>
> However, after the job was complete, the disc brakes stop the vehicle
> MUCH more poorly than the old drums. In fact it's now quite dangerous
> to drive. There is now absolutely no resistance in the first 2/3 of
> the brake pedal. There is finally some resistance and grab in the
> last 1/3 of the pedal, but even mashed all the way to the floor, the
> brake pedal only gives me a moderately effective stop. If I get into
> a freeway situation requiring quick braking, I will be in very serious
> trouble.
>
> I do seem to be able to get more resistance by quickly pumping the
> brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> noticeably harder, but it still isn't super great for stopping.
>
> The guy who did the work said that he suspects the problem is the
> master cylinder. He claims that the stock master cylinder on CJs is
> probably just not high enough capacity to handle the additional
> demands of the rear disc brakes, and that I could fix the problem by
> upgrading to a higher capacity master cylinder. I don't know nearly
> enough about mechanics to know if this is good advice or not
> (otherwise I would have done the job myself...) so can anyone here
> tell me if this is a reasonable answer? If so, any suggestions on
> what master cylinder to use as a replacement? If not, any other
> ideas?
>
> The guy who did the work came highly recommended by many local jeepers
> and has been popular with local jeep clubs for 20+ years, so I tend to
> think it's not just a case of him doing shoddy work or rippig me off.
> ( He assured me that he topped off the brake fluids, bled the brakes,
> and did everything else properly.) Unfortunately I can't take it back
> to him since I moved 1100 miles away immediately after this work was
> done.

 

I would properly bleed the brakes first:

http://www.stu-offroad.com/misc/brakebleed.htm

As indicated in this guys method, start from the longest line.

--
JimG
80' CJ-7 258 CID
35" BFG MT on 15x10 Centerlines
D44 Rear, Dana 30 Front. SOA
4.56 Gears, LockRight F&R
Dana 300 w/4:1 & Currie twin sticks
Warn X8000i w/ dual batteries

"sm3gurpal" <elambeth@hotmail.com> wrote in message
news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> I recently hired a guy to convert the rear brakes on my 82 CJ from
> drum to disc. (There was nothing wrong with the drums, I just had
> some spare cash burning a hole in my pocket.)
>
> However, after the job was complete, the disc brakes stop the vehicle
> MUCH more poorly than the old drums. In fact it's now quite dangerous
> to drive. There is now absolutely no resistance in the first 2/3 of
> the brake pedal. There is finally some resistance and grab in the
> last 1/3 of the pedal, but even mashed all the way to the floor, the
> brake pedal only gives me a moderately effective stop. If I get into
> a freeway situation requiring quick braking, I will be in very serious
> trouble.
>
> I do seem to be able to get more resistance by quickly pumping the
> brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> noticeably harder, but it still isn't super great for stopping.
>
> The guy who did the work said that he suspects the problem is the
> master cylinder. He claims that the stock master cylinder on CJs is
> probably just not high enough capacity to handle the additional
> demands of the rear disc brakes, and that I could fix the problem by
> upgrading to a higher capacity master cylinder. I don't know nearly
> enough about mechanics to know if this is good advice or not
> (otherwise I would have done the job myself...) so can anyone here
> tell me if this is a reasonable answer? If so, any suggestions on
> what master cylinder to use as a replacement? If not, any other
> ideas?
>
> The guy who did the work came highly recommended by many local jeepers
> and has been popular with local jeep clubs for 20+ years, so I tend to
> think it's not just a case of him doing shoddy work or rippig me off.
> ( He assured me that he topped off the brake fluids, bled the brakes,
> and did everything else properly.) Unfortunately I can't take it back
> to him since I moved 1100 miles away immediately after this work was
> done.

 

I would properly bleed the brakes first:

http://www.stu-offroad.com/misc/brakebleed.htm

As indicated in this guys method, start from the longest line.

--
JimG
80' CJ-7 258 CID
35" BFG MT on 15x10 Centerlines
D44 Rear, Dana 30 Front. SOA
4.56 Gears, LockRight F&R
Dana 300 w/4:1 & Currie twin sticks
Warn X8000i w/ dual batteries

"sm3gurpal" <elambeth@hotmail.com> wrote in message
news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> I recently hired a guy to convert the rear brakes on my 82 CJ from
> drum to disc. (There was nothing wrong with the drums, I just had
> some spare cash burning a hole in my pocket.)
>
> However, after the job was complete, the disc brakes stop the vehicle
> MUCH more poorly than the old drums. In fact it's now quite dangerous
> to drive. There is now absolutely no resistance in the first 2/3 of
> the brake pedal. There is finally some resistance and grab in the
> last 1/3 of the pedal, but even mashed all the way to the floor, the
> brake pedal only gives me a moderately effective stop. If I get into
> a freeway situation requiring quick braking, I will be in very serious
> trouble.
>
> I do seem to be able to get more resistance by quickly pumping the
> brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> noticeably harder, but it still isn't super great for stopping.
>
> The guy who did the work said that he suspects the problem is the
> master cylinder. He claims that the stock master cylinder on CJs is
> probably just not high enough capacity to handle the additional
> demands of the rear disc brakes, and that I could fix the problem by
> upgrading to a higher capacity master cylinder. I don't know nearly
> enough about mechanics to know if this is good advice or not
> (otherwise I would have done the job myself...) so can anyone here
> tell me if this is a reasonable answer? If so, any suggestions on
> what master cylinder to use as a replacement? If not, any other
> ideas?
>
> The guy who did the work came highly recommended by many local jeepers
> and has been popular with local jeep clubs for 20+ years, so I tend to
> think it's not just a case of him doing shoddy work or rippig me off.
> ( He assured me that he topped off the brake fluids, bled the brakes,
> and did everything else properly.) Unfortunately I can't take it back
> to him since I moved 1100 miles away immediately after this work was
> done.

 

I would properly bleed the brakes first:

http://www.stu-offroad.com/misc/brakebleed.htm

As indicated in this guys method, start from the longest line.

--
JimG
80' CJ-7 258 CID
35" BFG MT on 15x10 Centerlines
D44 Rear, Dana 30 Front. SOA
4.56 Gears, LockRight F&R
Dana 300 w/4:1 & Currie twin sticks
Warn X8000i w/ dual batteries

"sm3gurpal" <elambeth@hotmail.com> wrote in message
news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> I recently hired a guy to convert the rear brakes on my 82 CJ from
> drum to disc. (There was nothing wrong with the drums, I just had
> some spare cash burning a hole in my pocket.)
>
> However, after the job was complete, the disc brakes stop the vehicle
> MUCH more poorly than the old drums. In fact it's now quite dangerous
> to drive. There is now absolutely no resistance in the first 2/3 of
> the brake pedal. There is finally some resistance and grab in the
> last 1/3 of the pedal, but even mashed all the way to the floor, the
> brake pedal only gives me a moderately effective stop. If I get into
> a freeway situation requiring quick braking, I will be in very serious
> trouble.
>
> I do seem to be able to get more resistance by quickly pumping the
> brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> noticeably harder, but it still isn't super great for stopping.
>
> The guy who did the work said that he suspects the problem is the
> master cylinder. He claims that the stock master cylinder on CJs is
> probably just not high enough capacity to handle the additional
> demands of the rear disc brakes, and that I could fix the problem by
> upgrading to a higher capacity master cylinder. I don't know nearly
> enough about mechanics to know if this is good advice or not
> (otherwise I would have done the job myself...) so can anyone here
> tell me if this is a reasonable answer? If so, any suggestions on
> what master cylinder to use as a replacement? If not, any other
> ideas?
>
> The guy who did the work came highly recommended by many local jeepers
> and has been popular with local jeep clubs for 20+ years, so I tend to
> think it's not just a case of him doing shoddy work or rippig me off.
> ( He assured me that he topped off the brake fluids, bled the brakes,
> and did everything else properly.) Unfortunately I can't take it back
> to him since I moved 1100 miles away immediately after this work was
> done.

 

I may be wrong, but I thought the rear disk brake conversion required a
different proportioning valve. Anyone?

Tom

"Ichabod Shagnasti" <murfysflaw@nospamhere.com> wrote in message
news:7SXJb.597$PL5.277423270@newssvr11.news.prodig y.com...
> I'd tend to think he's right or there's still some air in the lines. I've
> had several MCs go out immediately after brake jobs, particularly on older
> cars, so it could be a case of that instead of it just being too small.
I'd
> try having the lines bled again just to be sure, and if that doesn't fix
it,
> upgrade the MC.
>
> "sm3gurpal" <elambeth@hotmail.com> wrote in message
> news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> > I recently hired a guy to convert the rear brakes on my 82 CJ from
> > drum to disc. (There was nothing wrong with the drums, I just had
> > some spare cash burning a hole in my pocket.)
> >
> > However, after the job was complete, the disc brakes stop the vehicle
> > MUCH more poorly than the old drums. In fact it's now quite dangerous
> > to drive. There is now absolutely no resistance in the first 2/3 of
> > the brake pedal. There is finally some resistance and grab in the
> > last 1/3 of the pedal, but even mashed all the way to the floor, the
> > brake pedal only gives me a moderately effective stop. If I get into
> > a freeway situation requiring quick braking, I will be in very serious
> > trouble.
> >
> > I do seem to be able to get more resistance by quickly pumping the
> > brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> > noticeably harder, but it still isn't super great for stopping.
> >
> > The guy who did the work said that he suspects the problem is the
> > master cylinder. He claims that the stock master cylinder on CJs is
> > probably just not high enough capacity to handle the additional
> > demands of the rear disc brakes, and that I could fix the problem by
> > upgrading to a higher capacity master cylinder. I don't know nearly
> > enough about mechanics to know if this is good advice or not
> > (otherwise I would have done the job myself...) so can anyone here
> > tell me if this is a reasonable answer? If so, any suggestions on
> > what master cylinder to use as a replacement? If not, any other
> > ideas?
> >
> > The guy who did the work came highly recommended by many local jeepers
> > and has been popular with local jeep clubs for 20+ years, so I tend to
> > think it's not just a case of him doing shoddy work or rippig me off.
> > ( He assured me that he topped off the brake fluids, bled the brakes,
> > and did everything else properly.) Unfortunately I can't take it back
> > to him since I moved 1100 miles away immediately after this work was
> > done.
>
>

 

I may be wrong, but I thought the rear disk brake conversion required a
different proportioning valve. Anyone?

Tom

"Ichabod Shagnasti" <murfysflaw@nospamhere.com> wrote in message
news:7SXJb.597$PL5.277423270@newssvr11.news.prodig y.com...
> I'd tend to think he's right or there's still some air in the lines. I've
> had several MCs go out immediately after brake jobs, particularly on older
> cars, so it could be a case of that instead of it just being too small.
I'd
> try having the lines bled again just to be sure, and if that doesn't fix
it,
> upgrade the MC.
>
> "sm3gurpal" <elambeth@hotmail.com> wrote in message
> news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> > I recently hired a guy to convert the rear brakes on my 82 CJ from
> > drum to disc. (There was nothing wrong with the drums, I just had
> > some spare cash burning a hole in my pocket.)
> >
> > However, after the job was complete, the disc brakes stop the vehicle
> > MUCH more poorly than the old drums. In fact it's now quite dangerous
> > to drive. There is now absolutely no resistance in the first 2/3 of
> > the brake pedal. There is finally some resistance and grab in the
> > last 1/3 of the pedal, but even mashed all the way to the floor, the
> > brake pedal only gives me a moderately effective stop. If I get into
> > a freeway situation requiring quick braking, I will be in very serious
> > trouble.
> >
> > I do seem to be able to get more resistance by quickly pumping the
> > brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> > noticeably harder, but it still isn't super great for stopping.
> >
> > The guy who did the work said that he suspects the problem is the
> > master cylinder. He claims that the stock master cylinder on CJs is
> > probably just not high enough capacity to handle the additional
> > demands of the rear disc brakes, and that I could fix the problem by
> > upgrading to a higher capacity master cylinder. I don't know nearly
> > enough about mechanics to know if this is good advice or not
> > (otherwise I would have done the job myself...) so can anyone here
> > tell me if this is a reasonable answer? If so, any suggestions on
> > what master cylinder to use as a replacement? If not, any other
> > ideas?
> >
> > The guy who did the work came highly recommended by many local jeepers
> > and has been popular with local jeep clubs for 20+ years, so I tend to
> > think it's not just a case of him doing shoddy work or rippig me off.
> > ( He assured me that he topped off the brake fluids, bled the brakes,
> > and did everything else properly.) Unfortunately I can't take it back
> > to him since I moved 1100 miles away immediately after this work was
> > done.
>
>

 

I may be wrong, but I thought the rear disk brake conversion required a
different proportioning valve. Anyone?

Tom

"Ichabod Shagnasti" <murfysflaw@nospamhere.com> wrote in message
news:7SXJb.597$PL5.277423270@newssvr11.news.prodig y.com...
> I'd tend to think he's right or there's still some air in the lines. I've
> had several MCs go out immediately after brake jobs, particularly on older
> cars, so it could be a case of that instead of it just being too small.
I'd
> try having the lines bled again just to be sure, and if that doesn't fix
it,
> upgrade the MC.
>
> "sm3gurpal" <elambeth@hotmail.com> wrote in message
> news:88f4ec61.0401040704.28a99f35@posting.google.c om...
> > I recently hired a guy to convert the rear brakes on my 82 CJ from
> > drum to disc. (There was nothing wrong with the drums, I just had
> > some spare cash burning a hole in my pocket.)
> >
> > However, after the job was complete, the disc brakes stop the vehicle
> > MUCH more poorly than the old drums. In fact it's now quite dangerous
> > to drive. There is now absolutely no resistance in the first 2/3 of
> > the brake pedal. There is finally some resistance and grab in the
> > last 1/3 of the pedal, but even mashed all the way to the floor, the
> > brake pedal only gives me a moderately effective stop. If I get into
> > a freeway situation requiring quick braking, I will be in very serious
> > trouble.
> >
> > I do seem to be able to get more resistance by quickly pumping the
> > brake pedal a couple of times; on the 2nd or 3rd pump the pedal gets
> > noticeably harder, but it still isn't super great for stopping.
> >
> > The guy who did the work said that he suspects the problem is the
> > master cylinder. He claims that the stock master cylinder on CJs is
> > probably just not high enough capacity to handle the additional
> > demands of the rear disc brakes, and that I could fix the problem by
> > upgrading to a higher capacity master cylinder. I don't know nearly
> > enough about mechanics to know if this is good advice or not
> > (otherwise I would have done the job myself...) so can anyone here
> > tell me if this is a reasonable answer? If so, any suggestions on
> > what master cylinder to use as a replacement? If not, any other
> > ideas?
> >
> > The guy who did the work came highly recommended by many local jeepers
> > and has been popular with local jeep clubs for 20+ years, so I tend to
> > think it's not just a case of him doing shoddy work or rippig me off.
> > ( He assured me that he topped off the brake fluids, bled the brakes,
> > and did everything else properly.) Unfortunately I can't take it back
> > to him since I moved 1100 miles away immediately after this work was
> > done.
>
>