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Hi-
Question: if you were rebuilding your brake system, what components would you use to minimize future problems? Are there any upgrades above OEM for any components that increase performance/longevity of the system?
Reason for the question:
I've had a series of brake problems on my 240.
If I get the system bled once a month, it works ok. Otherwise, it acts like there is a bubble in the system. Symptoms are a pedal that will go almost down to the floor when I first depress it, and if I pump it up a few times, then it works ok. However, every time I get the brakes bled, the pedal feels almost like a rock - almost no play between a gentle brake and a grab almost engage abs feeling. And then within a month, same problem.
It also seems to be burning through brake pads very fast - about 6 months or so, and I'm not a very aggressive driver.
And now the rear end is shaking like crazy when I brake - maybe a warped rotor, who knows.
So I'm fed up.
I'm thinking about putting in new brake lines, new rotors, new pads, and new calipers, maybe new valves and cylinder?
The other reason for the massive change is that I am going on long driving vacation, and don't want to be dealing with problems on the road. After vacation, I'm moving away from the one indie shop that I trust.
If (when) I mess up the rebuild or find a piece that is not feasible for a rookie car repair guy in the driveway, I'd like to have them fix the damage!
Thanks for any suggestions/ comments
p.s. I'm running stock steel 14" wheels, so no massive upgrade is likely to fit in there.
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I would first check for a stuck caliper front and rear, replace/rebuild as necessary. Then I would install a new master cylinder (M/C) for the sinking/mushy pedal problem (if no fluid leaks are found anywhere). Replacing everything (all rubber hoses, rebuild/replace calipers, new M/C, new pads and resurface/or new rotors) is also an option if you have the funds and the car has lots of miles, but shouldn't really be necessary. That is the obvious complete fix if you are building a "keeper." But I really have a feeling it is your M/C going bad AND maybe a stuck caliper, causing your troubles. You don't need upgrades, just new standard items, the original setup is more than adequate.
Charles
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Sounds like one of your calipers is hanging up. Causing the Pads and Fluid to heat up to the boiling point, giving you that mushy pedal every month.
Are all the Pads wearing out or just one side or maybe just the rears?
A hung up caliper would also cause the Rotor to over heat and warp, giving you the shake in the rear. When you compress the Pistons, They all go in easy enough?
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm
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Something's way wrong here. I'd pull the wheels off and see what's happening with the pads. If they're not wearing evenly, you may have some seized caliper pistons, maybe a rotted bleeders, or some other openings in the system. Old flexible hoses could be a problem as well.
Best thing you can do (partswise) for replacements for day to day driving is rebuilt calipers and new OEM quality bits wherever else it needs them.
Honestly, this is a pretty serious (and potentially disastrous) problem, and if this indie shop you trust hasn't advocated or tried to track this problem down, I'd be switching shops anyways. You just don't roll the dice with the brake system.
Good luck!
-Ryan
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Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars
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It's kind of a mystery.
First, the pads were worn, so I replaced them. Calipers seemed to work fine.
Then pedal got mushy. I figured that there was air trapped in the lines somewhere, and got them bled.
Then pedal seemed to "hard" for lack of a better word. But the problem went away.
I've been religiously checking the brake fluid levels, and no change, so no perceptible leak. I've cleaned the engine compartment and everything that I could reach around the wheels to make leak tracing easy, haven't found any evidence of a leak anywhere. I've put clean cardboard under the car, stomped on the brake pedal over and over and over again in hopes of finding a leak, no drips on the cardboard.
But the cycle of pads getting consumed fast, brakes cycling between mushy and hard, and constant checks of the calipers has revealed nothing. Calipers move freely every time I check, and everytime the indie checks.
I'm stumped. Could there be gunk in the lines that is causing this?
My understanding of the brake system is really limited.
Step on brake, push fluid in lines, pressure compresses calipers, calipers push pads onto rotor, car slows.
Calipers are free, pressure is getting to calipers (intermittently), so I'm leaning towards new lines. Otherwise, it is some part of the system that I don't understand, which translates into "replace it all" for me.
Thanks for the thoughts - any more ideas are welcome!
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Okay, you have caused my brain to go into the "way-back machine"... thanks a lot! What did I do to try and resolve this exact same problem, you ask? Here is the list:
Rebuilt calipers
Rebuilt MC
Replaced rubber flex lines with SS braid
New pads
New rotors
New hardware
Rebuilt distribution block
Found qty. 0 nada/zip/squat for leaks, all was good
The result was that the brakes worked fine for about a week with a stiff pedal, then it felt normal for a week. After that it went mushy and pumping was needed (sound familiar)? Add in warped rotors, bad gas mileage and worn brake pads in the 3K mile range that needed replacement, this car was heading to the crusher if I couldn't figure out the problem! The dealer was worthless (replace pads, bleed system, turn rotors), Indy shop didn't do squat other than charge money. Before giving up, I ran across an old friend, Jim, a Ford T-Bird maestro, I mentioned my dilemma and he started laughing in a good hearted way. At this point, I was trying to think of what part of the brake system I hadn't replaced, but Jim gave me the answer with a smile, simply replace the brake booster, it is either leaking vacuum on one side or the center section is sticking. His final words were quite simple... it sounds like Volvo copied the double bendix design that the 62 through 66 T-birds used, when they fail, the brakes don't fully release and the brakes get cooked! Drive it long enough that way and the car won't move as a result!
To verify this, try pulling a vacuum on the booster port, if the vacuum won't hold for at least a few hours you have the answer. If the vacuum test is good, remove the MC and press the brake pedal to the floor, now try pushing the push rod that normally hit the MC back into the booster, does it move smoothly, or does it drag? If so, it is time for a new booster.
Note that booster replacement is a PITA, so make certain it is bad before you do so!
jorrell
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92 245 250K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!
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Yay!
What you described matches my symptoms exactly. This is why I love this site - someone has suffered every indignity that the brick can throw at you, and is happy to tell the story of how to fix it.
I'll try the tests that you suggest, and see if it is time to replace the booster.
Thanks!
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There have been a few instances reported here of degraded flex brake lines acting as check valves. It's hard to envision that happening uniformly aon all 4 calipers, but - "never say never." I've got SS braided lines on order myself for my '92... just trying to avoid problems. Soft parts have shorter lives out here in the desert!
--
Thank goodness we don't get all the government we pay for. -- Will Rogers
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Worn seals in the master cylinder are a liklely cause of the intermittent mushy pedal. This is not unlikely if the cylinder is original.
Another original part likely to cause trouble after 15 years is the front brake hoses. They swell up on the inside (usually where the clamp is) and become constricted. This prevents the pistons from retracting properly, (even if there is nothing wrong with the caliper itself) which burns up the pads in a hurry.
I would recommend replacing both the master cylinder and all the flexible lines, followed by a thorough bleeding with a pressure bleeder, especially if any/all of these components are original. If this fixes it, great, if not, there's probably a problem with one or more calipers.
Vibration/shuddering while braking is usually caused by a warped rotor (or two) though if it seems to be coming from the rear, you should also take a look at the trailing arm bushings.
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