Brake Bleeding woes on 93 XJ-TSM rear disk kit

Never seen one like this before. My buddy swapped in an M20 rear that has a TSM disc kit on it using Caddy calipers. The brakes seemed fine after the rear swap, but then when we installed some longer SS front brake lines, we just couldn't get the a good firm pedal. We bled each cornerwell, working in the proper pattern. What hasn't been done is the prop. valve mod that removes the o-ring for better fluid valving to the rear, but the brakes worked fine before the new front lines went on. Bleeding them again is next on my list, but any insight from others that have a similar setup is welcome.
(Heading to Moab in 4 days....need to get this done!)
TIA
XJEEPER

If somehow you got a little air into the rear calipers...

Take a close look at the rear calipers -- you'll notice that the bleeders are most likely NOT on the top so any/all air will not be expelled -- if that's the case, to bleed the calipers you'll have to pull em and invert em so that the bleeder is at the top of the cylinder!

Not that common that a front system change will introduce any air to the rear system, but depending on howlong things were opena d how the bleed was done and all, it's a possibility...

satan said:

If somehow you got a little air into the rear calipers...

Take a close look at the rear calipers -- you'll notice that the bleeders are most likely NOT on the top so any/all air will not be expelled -- if that's the case, to bleed the calipers you'll have to pull em and invert em so that the bleeder is at the top of the cylinder!

Click to expand...

Granted it was 11pm on Monday when I noticed this during the "bleedfest"......the bleeder is in an odd spot for getting rid of the air.......

XJEEPER

This may sound stupid, but how about swapping back to the original lines up front. I have heard that the stainless lines can feel spongy. At least you can get back to the good feel you had before and go from there. Maybe some longer rubber brake lines would work better.

Generally stainless lines give a firmer pedal feel....

On my '98....

I did the TSM rear disc mod last year. Those calipers are mounted with the bleeders about in as perfect a position as possible. Had no problem whatsoever bleeding out the system. Rem if using two people, pump the pedal SLOWLY releasing your foot at the top of the stroke to make sure the piston has a good chance to pull fluid back into the system. Cannot imagine why the addition of SS brakelines would cause a problem- if they are the correct ones. Normally they are known for helping to create a more firm pedal. I would bet you are simply using bad procedure not being careful enough.

I know the system on that '93 is different than mine, but if was a good pedal before should be able to be achieved again.

XJCHRIS said:

This may sound stupid, but how about swapping back to the original lines up front. I have heard that the stainless lines can feel spongy. At least you can get back to the good feel you had before and go from there. Maybe some longer rubber brake lines would work better.

Click to expand...

Thanks for the tip Chris, good basic troubleshooting, return to your baseline to help isolate the problem.

The reality is that rubber lines will feel more spongy through the pedal due to their ability to swell when pressurized. Some like rubber over SS for it's ability to stretch if overextended during articulation, other say dial in your suspension properly so the brakelines are not functioning as a droop limiting strap.....

I run extended length SS lines and noted a much firmer pedal feel than with the rubber lines. My inclination is to rebleed the entire system and the problem will be resolved.
Thanks all for the input.

XJEEPER

I had that system and had mucho problems w/ the same thing.

Its the parking brake adjustment that keeps coming off. The system from the factory was poor back then and its not any better today. Look at modern rear calipers they all have a drum style parking mech. incorporated into them.

If the e brake is not adjusted right it will give a soft pedal.... the problem with them is, you can adjust them one day and 3 days later they come out of adjustment....thus the reason no one uses that style of caliper on any new car.

My research AFTER i bought it showed just how poor of an idea that system is. Problem is people spend $700 on rear disks and dont want to admit they got had!

Not to mention TSM has THE WORST customer service. I cant imagine how theyve stayed in business this long. I had several problems w/ my kit and had to buy the missing parts at MY cost, fix their mistakes, that they admitted to, AT MY COST!

Skip @ TSM said "Dont you ever make mistakes at your job? you must be perfect" He expected me to fix his mistakes at my cost!
Fawkin unreal..... i have never done business w/ anyone like that.

Xjeeper..... if you dont have the Ebrake model this may not apply ... if you still have problems email me and ill give ya a call ...i learned a lot after tinking around w/ poor brakes for 3 weeks

regards
adam