i have a problem where my 240 wgn pulls to the right when i brake. it drives straight when not braking, so i am fairly certain its not alignment. from the research i did here and a few posts i was thinking it was a bad piston on one of the calipers. today, my mechanic tells me he thinks it is because i have 2 different types of calipers on the front brakes. is this likely? he already replaced the brake lines to the calipers with no results.

thanks for the advice!

Does your car have abs? If so then you get rid of the 3 nipple caliper and also ditch your mechanic. Information is your best defense. You'll find accurate information here. Good Luck.
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92 244 lowered, Bilsteins, IPD sways, Unitek cam/header, TSW Revo 18x8's - 94 965 Niiice MONEY PIT! - 76 Datsun 280Z lowered, modified head, cam, headers, intake

Hello,

There are no floating pins on 240 calipers.

It is not suspension, otherwise it would pull all the time getting worse with an increase in speed.

Your mechanic is probably hosing you because brake lines would not be the culprit in this case. BTW - did he replace them with some nice braided lines?

It seems to me that the left caliper is seized or partially seized. What is the culprit here is lack of brake component maintenance. A simple thing called a brake service. I'll run you through what needs to be done once a year if you live in the south, twice if you are up north with cold weather and/or salt.

1) Jack up one side pop off the wheel and remove the brake fluid cover.

2) Take out the cotter pins holding the larger pins that support the pads. Remove the larger pins taking care not to lose the part shaped like a big one of these { }, DO NOT REMOVE THE PADS YET.

3) Use a large flat head screw driver to push back all 4 pistons. Now get in the car and depress the brake pedal all the way. Repeat this 3 or 4 times to properly excercise all the caliper pistons.

4) Remove the pads, clean everything with spray brake cleaner.

5) Coat the pad backings, shims, pins and caliper pistons with brush on brake grease or anti-seize compound.

6) Using very coarse emery cloth or sandpaper (50 or 75 grit), scuff the pad and rotor surfaces evenly.

7) Reassemble everything and repeat on the other side.

8) Make sure the brake fluid reservoir is topped up.

The first time you hit the brakes, you may get a little more travel on the pedal, but that should tighten up almost immediately. You may also get a little grinding as well, but that's just the pads and rotors settling in again.

There should not be an issue with the right caliper. You may be able to coax the left one back to life. DO NOT HEAT IT TO UNSEIZE IT!!! You will melt the rubber seals around the pistons. Rebuilt calipers aren't so bad costwise, but your mechanic will have to replace it unless you know how to bleed the brakes after.

With this simple 1/2 hour job one can keep that nice firm, strong feel of the brakes indefinetely, plus it makes the pads last a lot longer, and the rotors indefinietely.

Happy Bricking!!!!

Richard
Toronto, Ont.

87 245 DL 349,000 km (over 100,000 km on PBR pads and cheapie UAP rotors - no signs of significant wear)
82 242 GLT 121,000 km

Richink's process appears to be good advice for general brake maintenance.

"today, my mechanic tells me he thinks it is because i have 2 different types of calipers on the front brakes. is this likely?"

First thing I'd do is jack up the car, put it on stands and check for myself.

"he already replaced the brake lines to the calipers with no results."

Why would he have replaced the brake lines, before he checked the calipers?

Not sure what you mean by "2 different calipers." Different brands? About the only difference I can think of is that you might have a non-ABS caliper on one side and an ABS caliper on the other side - but it would be almost criminal for someone to do that. The ABS units have a single brake line feeding them, whereas the older non-ABS have 2 lines (and 3 bleeder screws). However, rebuilt calipers are not all that expensive (maybe $60-70 each) and eminently replaceable by the careful shadetree mechanic. You might consider replacing one caliper so both are the same.

Has your mechanic actually checked the pistons in the front calipers? There are 4 pistons per caliper, so if just one is frozen it might not be obvious. If the pulling just started, it might be too soon to see uneven pad wear, but that will happen eventually.

Assuming for a moment that there is no difference in front calipers, what would make you car pull while braking? Worn suspension parts (ball joints and front A-arm bushings come to mind) and incorrect toe-in could be responsible.

this is exactly what he described. one with 3 bleeder screws and one with one. the 92s should have ABS calipers, right? wish he had checked this first.

i just got the car a few months ago, it sounds like the previous owner was either hosed by his mechanic or screwed it up himself.

thanks everyone for the help.

The '92's have ABS and hence the correct calipers have a single bleed screw. I suspect internal porting may be different between the 2 types, and the 3-bleeder caliper is not pulling its own share of the braking. Time for a new (rebuilt) caliper and new pads.

Wonder what other surprises await you... at least here, you're talking to the right people.

In the 700 series, there are two different types of front calipers: they are Bendix and Girling.

I am not sure if that is the case with the 200 series, but if so, that may be what your mechanic is talking about.

Furthermore, your caliper may have stuck floating pin if you have those. A stuck floating pin may cause problems such as what you are describing. The floating pins (2 on each caliper) should be loose and move freely. If not, then they are seized and need to be unseized. Assuming you have these, of course.
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Kenric Tam
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'