Brake problem, am I on the right track?

Hi all...

the brakes on my '99 have sucked ever since I got it. On purchase, the brakes felt OK through the pedal but required more force than a normal car to stop. When I got home and ran the vehicle through inspection I was told that the fronts were below legal limits, so I quickly replaced pads and rotors to pass. At that time I flushed the brake fluid as well but did nothing else. I then found that the brakes were beyond awful. Had rear shoes adjusted and then they were back to "OK" again but not great. I've put about 10K miles on the vehicle since then.

The other day I was coming home from a job and suddenly my pedal dropped; now it is slightly mushy and if anything stops better but the feel is really disconcerting; when I take up the free play in it it doesn't really stop well at all, then I push through the "mush" and it stops if anything better than it has been, but the feel is unacceptable.

I told my shop owner friend to order me all new hoses, a hardware (slider) kit for the front brakes, and new rear shoes and springs (the latter because I know they're thin, every year I'm told they're "almost worn out" but never actually are. I know the rear brakes are working though because the drums get warm when driving.)

I do not see any evidence of calipers leaking. I'm ASSuming that bad/constricted hoses are the source of all my problems, but I want to replace the hardware as well just in case something is sticking.

This vehicle *does* have ABS but no ABS codes.

Do you think I'm covered, or is there a possibility that there is something else wrong?

You should have it covered. Usually it's just the adjustment of the rear brake shoes.

First do rear brakes.

Are you sure you bled the system properly? Bleed it good and properly. Make sure the front calipers are not leaking. Next consider the MC. they are cheap and easy to replace.

yes, I used my Motive Products bleeder and ran fluid through until it looked new, even though I didn't open anything up. If the fronts are leaking I can't see it, at least not without racking it and pulling stuff apart. Don't think it is the MC as the pedal doesn't move at all when stopped at a light.

It really feels like I've had an issue with hoses for a long time but neither I nor anyone else that's looked at it identified it. Maybe I inadvertantly damaged a hose when changing the pads and have just been "dealing with it" ever since? But then how did I bleed the brakes? (scratches head)

It sounds like you are compensating for poor front brakes with the rear brakes. The rear brakes should outlast the fronts by probably 3 times.

I might be tempted to take a look at your master cylinder. You can have the front pump not being up to snuff, but the back portion working fine.

Is your brake booster working?

yes booster is working. I can pump up brake pedal with engine off, then start engine with foot on pedal and feel it drop.

I really don't want to replace MC as I don't think that it's bad and then I'd have to get someone with a proper dealership scan tool to bleed my brakes for me because I don't have the tools to cycle the valves in the HCU.

I'm just really frustrated and doubly so because I don't think my "friend" ordered my parts for me which means I'll end up working on this in my driveway because it's over an hour's drive to his shop and if he doesn't have the parts by the time I get there it's not worth it as then I won't have enough time to finish the work before he closes

To elaborate on how the pedal feels now, it feels like one circuit of the brakes is kicking in first, then some slack is being taken up, then the other circuit is kicking in - exactly like rear brakes very out of adjustment and/or a small air bubble in one circuit. Now I'm starting to second guess myself and wonder if something has broken in the rear brakes causing them to suddenly go out of adjustment (parking brake strut? Parking brake arm pin?)

Edit: hah. I was right. he just called me asking me "which caliper do you need, left or right?" SMH. Made the right call sitting here on my butt instead of heading over to shop. Of course it's 37 degrees outside now and it's supposed to snow tomorrow. Got to get this fixed because I have an interview Tuesday morning at a repair shop of all places. FML

Well I went to NAPA this morning and found that the parts were cheap (semi-loaded front calipers with a nice black paint finish were $20-something apiece) so I'm going scorched earth on this thing... new calipers, all hoses, rear shoes, hardware, and wheel cylinders. As I said before front rotors and pads have about 10K miles on them and look good.

Good news: I got the fronts all done and back together. Hoses came off fine, didn't have to fab any lines.

Bad news: I bled the fronts and then went for a little drive; the brakes feel EXACTLY the same. Really not confidence inspiring at all. Yeah, I live in NoVA where having excellent brakes is kind of a requirement.

So I'm going to have an adult beverage, then go back outside and put the rear up in the air... gotta do the shoes anyway before the end of next month so never been a better time than right now eh?

If I don't see any problems with the parking brake strut etc. and it doesn't feel any better after I get it back together, I guess it will be master cylinder time... because once I'm done with this the only original components other than hard lines left will be the MC and the HCU (and if it's the latter I might just go ahead with an ABS delete and 8.25 or 8.8 swap)

My brakes started acting up on my jeep. I checked everything and i mean everything.I had a spare brake booster sitting in my garage, so i installed it and now i have better brakes. I did the test you're talking about and it did the same thing. Maybe you should think of trying a new one. Mine had about 150 thou on it.

HTH

I don't see how a booster would cause the brakes to suddenly be spongy though when they used to be rock hard firm? Unfortunately while enjoying my adult beverage the shiny thing in the sky went away, so I guess I'll be ripping the rears apart in the snow tomorrow. And then if after getting that all together and the brakes still suck I'll replace the MC. Actually I should probably check the hose to the booster for brake fluid before I rip the rears apart, so if there's any evidence of leaking I can just swap the MC at the same time the rears are apart and only have to bleed once.

I don't feel like I wasted my money yet though because I've also had an intermittent vibration problem and the only person who's looked at it that offered any suggestions said he thought one of my front calipers was hanging up intermittently, the new calipers and hoses added up to less than an hour's labor at a shop so shotgunning is not really that dumb here, and I will need the new rear shoes anyway to pass inspection, so the only extraneous parts I bought are the rear hose and wheel cylinders, and the thing's 15 years old anyhow so I feel better with new hoses...

I've only got 90K miles - literally just turned 90K a few days ago - so I'm a little disappointed that I'm having all these problems at this point. But hopefully if I get it all fixed up I won't have to worry about brakes again for a good long time.

Bad news: if I have to run to the parts store, my only other vehicle is a BMW 335i (*not* 335i Xdrive)

Good news: Blizzaks + massive amounts of torque + manual transmission + RWD + snow = fun, long's the cops aren't watching

Clamp off the three brake hoses and see if the pedal still moves.it shouldn't move at all. If it sinks, attempt to rotate each wheel to eliminate the possibility of a loose clamp. If all four wheels move freely, the master cyl. Is your best bet.

I don't think that the hcu is a big deal bleeding wise. I don't recall having to do any special bleed procedures. Worse case. Take it out into an empty lot and do a few ABS stops, then rebleed.


Oh, and to cover my a$$, make sure the bleeders on the calipers are pointed up. Can't tell how many times I've caught people not paying attention and mounting them upside down.

ABS stops? you're funny...

seriously, I don't think I would have ever been able to activate ABS in this thing without a bleach box, even when everything was working correctly. I've been seriously considering ordering a set of the yellowstuff or black magic pads (are they really that good? They're stupid expensive...) because the brakes have ALWAYS been scary marginal. My old Studebaker with four wheel manual drums stops better than my XJ. I kind of wonder why ABS was even an option, the only reason I haven't bypassed it yet is that little liability-averse voice in the back of my head that's likely a result of years of working in construction for a Huge International Conglomerate...

Well, I got the rears apart and see no obvious issues... pulled the vacuum hose off booster and it's dry. Guess from here, just put all the new parts on, rebleed, try it again, and if it still sucks, replace the MC?

If it comes to that, where can I get a MC that's *not* made by A1 Cardone? I'm kind of hesitant to buy anything from them as I've had some bad experiences with their reman boosters in the past (not Jeep, but still.) Unfortunately A1 Cardone is all I seem to see available locally save for "Fenco" (who I've never heard of before) at VatoZone.

Edit: I'm listening to you guys, I didn't disregard some of your advice for no reason. Re: clamping off the hoses, that won't tell me anything because the pedal is rock solid once the vacuum is gone in the booster, and I already installed the two new front hoses so I don't want to clamp them. I did the fronts first because a) I wanted to do them anyway and b) there was a huge core charge on the calipers so I wanted to return them yesterday, and I had to go back anyhow because the NAPA store had to order in the rear hose.

Update: RR wheel cylinder had one stuck piston, and the self adjuster cable was rusted to its saddle, so I had to go *back* to NAPA and buy a pair of self adjuster kits. Not real impressed with them; I used the cables, saddles, and spring but kept my old star wheels and lever arm because the new NAPA stuff barely made contact. My star wheels are fine; this past summer I pulled the drums off and just removed the star wheels and anti-sleazed the threads as PM as it hadn't been done before.

In the house warming up, then I'll tackle the LR. BTW it's cold outside.

I don't think I'll try to replace the rear hose today. Barely got the hard line off the wheel cylinder, and I actually would feel better replacing it at this point, so the next nice day I'm going to plan on replacing the hard lines and the hose together. The fun never ends.

Ugh... been slogging on this way too long

finished up the install yesterday save for the drums, hard lines, and hose (left old hard lines and hose in place); my old drums had so big a rust ridge on them they wouldn't slide over the new shoes. Found one piston stuck in the *other* wheel cylinder as well, so only one piston on each side was working. Took the drums to NAPA this AM to get them turned, guy said "oh hell no I'm not turning those with that much rust, I'll send them out, it'll be 3-4 days" dammit! this thing has to work today! So bought two new drums, sat in traffic for close to two hours because the police had Leesburg Pike closed right past NAPA (don't know if it was a wreck or what?) got home, quick painted them and threw them in the oven to bake while I ate lunch, just got them installed, brewing another pot of coffee to warm up, once I get a cup in me it's time to bleed and adjust and see where I'm at.

Also stopped at Advance and picked up a stick of that copper-nickel brake line for when I do replace the hose. Seems nice, I hope it lives up to the hype. Thinking of ordering a box of stainless tube nuts because the usual failure mode (for me) is that the line is still solid but surface rust between the tube nut and the line locks them together meaning if you need to service something you have to replace the hard line that attaches to that component as well.

If I don't have good brakes after this I'm going to kick puppies.

FUNK!

looks like I'm fabbing hard lines TODAY not in a nice warm shop at my leisure.

Bled, started, hit brake pedal, sinks to floor. RR hard line hose to wheel cyl. failed right where I figured it would, underneath the tube nut. Probably ought to do both for insurance.

In retrospect, what I *should* have done was just honed and kitted the old wheel cylinders on the vehicle.

It's aliiiiiiiiiive! Apparently the messed up rear wheel cylinders were my problem... not broken in yet but they feel as good as ever *whew*