How To Diagnose and Replace a Faulty Caliper

[EricTheCarGuy]

I feel this is a fairly straightforward video but I welcome your comments.

Topic

[EricTheCarGuy]

If it was at my shop I would not have rebuilt the calipers. They could still be a problem. The truth is that you’re going to have to wait till after you install the hoses to find out if that’s the issue. You’ve already ordered them so you might as well put them on. After that you can assess if it’s a problem with the hoses or a problem with the calipers. If after you replace the hoses the problem is still there, then it’s reasonable to conclude the problem is with the calipers. If that’s the case, you’re going to have to replace them and recheck for the problem.

Be patient. Give it time. Replace the hoses and see what you have.

[Veiko]

Ok Eric thank you for replying.

But atm i see that you leave out the master completely?
Any particular reason?

Yes i used 2 bolts to close the outlets on the master completely and pedal was hard and not sinking.
Hard as rock. After connecting the 2 lines, pedal sinks.

Is that enough for you to leave out the master atm? Im just curious.

The other auto parts store gave me 3 days to figure out whats wrong and after that i can tell them to order new master or not.

And im thinking here, maybe i should buy new calipers instead of master then?

I know i shouldn’t rebuild or touch the calipers, they were sticking a bit but i had brakes.

But lately when i was driving i noticed that my brakes were getting a little bit weaker.
You know how it is, if you drive your car you know when some new noise appears somewhere or something changes while you drive.

And i noticed that brakes were getting weaker. I had to push more to stop the car quickly.
Maybe it was because of worn front brake discs and pads.

I will try to google, maybe there is a way to test calipers or something.

[Veiko]

I also found and ordered 2 rear wheel cylinders, old are leaking anyway and its time to replace them. I will get the hoses and cylinders tomorrow morning.
First i will replace the hoses and then the cylinders. Hoses first because i hope to see rock hard pedal after that.

If i dont see and it still sinks, too bad.
Then im out of ideas completely. It makes me mad, when i started messing with this all i just took out passenger side front caliper, took it apart, cleaned and it was waiting for new bushings / repair kit. When it arrived i used fresh brake fluid for them and put all together nicely and carefully.
Then i removed drivers side front caliper and did same. Then put everything back on the car, bleeded all wheels. Because rear drum brakes bleeders were so old and rusty i decided to replace them.
I searched for the new ones that were almost the same. There were few differences.

Im suspecting here that these slight differences may allow air into system or just dont go fully to the end. The thread was same on them but the hole in bleeder cone was in different position and the cone itself was not very similar.
So the bleeder is not probably all the way in cylinder.

Could that be possible Eric?

I still have old ones and may be i will put back the old ones if new cylinders dont come with new bleeders.
But then again, why if i squeeze the front hoses the pedal is hard. Strange thing.

It is possible to get new calipers but it takes few weeks and price is not very friendly.
Hopefully i dont have to buy new calipers or new master.

Tomorrow is the day.
I will also try to look under car where the brake lines go, maybe there is something to discover, i hope not.

Also i had idea here to remove one steel line from master and put a bolt instead and just leave one outlet connected to the line.
At the same time look at the proportioning valve, is it dry or not.

[EricTheCarGuy]

You’re replacing a lot of parts. You have replaced a lot of parts. It’s not really possible at this point for me to say what the issue is with your brakes unless I was able to look at them myself. The best advice I can give is to replace the parts that are leaking and install the parts you’ve already ordered. Once you’ve done that you can check those off the list of possible suspects. Keep in mind the more you mess with things on the brake system, the more potential problems you open up. I do not advocate rebuilding calipers because it often causes problems similar to what you’re having. I guess what I’m trying to say is that you may be causing this issue during the corse of your repair and creating more issues with each new thing you take apart or replace, so keep that in mind. Otherwise, you’re just going to have to keep us posted on what you find.

Good luck.

[Veiko]

I know Eric.
Like i said, i just will replace the hoses first, if it still sinks, i will replace rear cylinders, because they leak.
After that i will test for sinking again.

If it sinks, i will tell you.
I dont touch anything else atm and i will not touch until i will get the hoses and rear cylinders.

Thank You Eric for your patience with me and trying to help me.
I really appreciate your help and time.

Will give report tomorrow. Today i will not do anything. Too hot weather and im tired.

[Veiko]

Ok, replaced both flex hoses and nothing changed. Still sinks.
Very sad..

I didnt replace the rear wheel cylinders yet but i will eat and will do that.
When i removed my master few days ago, i didnt have the proper wrench for the nuts, i used the usual wrench to tighten them. I didnt round them off because of the small trick but now i have proper 10mm wrench for brakes. So i re-tighten the master outlets.

I did have small fluid leak at right side where the flex hose and steel line connect, there is that nut / bolt. But i tightened it more and now it doesnt leak.
So all i have left to do is change rear cylinders.

If it still sinks after that then Eric what you would do next?

Im wondering here, how the calipers can cause that, if they cause the problem.
They dont leak, they move like they should, i press brake, wheels do not move, i release pedal, wheels move freely.

I tried to squeeze again both lines at front but because they are new, i didnt use so much force, so pedal got hard again but slowly sinked down. Very slowly.
I repeat, i didnt tighten the new flex hoses too much with vise grips, i was afraid that i will break them. So this probably caused the pedal to sink slowly.

When i squeezed the old ones, i did it pretty hard because i didnt care about them much. And pedal was hard and not sinking.

So whats next Eric? Assuming rear cylinders are also new and pedal sinks as soon as i start the engine?

EDIT:
What do you think about clearance between brake booster push rod and primary piston?
What about vacuum hose check valve? If i remove vacuum hose from booster, can i hear something or see?
Pedal should get hard because there is no booster?

What about brake pedal height, brake pedal free play, clearance between brake pedal and floor board?

I never checked these things. Only measured how much pedal sinks with idling and not idling.

EDIT2
My repair manual has brake troubleshooting table.
Section:

Increased pedal stroke (Reduced pedal to the floorboard clearance)

Possible causes:
a) Air in brake system –> Bleed air from system
b) Worn lining or pad –> Replace
c) Broken vacuum hose –> Replace
d) Faulty master cylinder –> Replace
e) Brake fluid leaks –> Correct
f) Auto adjuster malfunction –> Adjust
g) Excessive push rod to master cylinder clearance –> Adjust

Underlines are most interesting for me.

Should check the vacuum hose.
Fluid leaks: yes i have them (leaks) at rear cylinders.
Air in brake system, i wish it was air that causes all the problems, air is free of cost.
Excessive clearance, maybe, i didnt check it, because i dont have the tool (caliper) to measure, have to find it first in my tools, caliper must be somewhere.

No word about calipers leaking but sad thing is that master is mentioned, the most expensive and hard to get part.

I also got some nice points to check or think about from here:
http://www.peachparts.com/shopforum/2037279-post23.html

[Veiko]

Tried to remove rear drivers side wheel cyl. but failed because of the rust.
I was able to break loose the connection between steel and flex hose but the cyl. side was so rusted i have to break it. And make a new piece between steel line and flex hose. I have the double flaring tool. Because otherwise its impossible. The 2 bolts that hold cyl. in place are also so rusted.
I was able to remove one, but the other one has so much rust on it so its almost like round head bolt now. I have to probably buy some needle nose vise grips to try to remove it. There is no room for big grips. The other way is to remove steel line connection from old cyl. do whatever it takes, because they are old, i dont care, i have new ones around and then just turn the cyl. at the other side.
Whatever way it goes.

But this will get me to nowhere. Im pretty sure.
It drives me nuts and i just want to fu*king drop it to the river with its brakes and master cylinders including calipers lol.

Really Eric. Im going to give up soon.

I squeeze the darn rear flex hoses, nothing changes, so what this will change if i will put new cylinders at rear? I guess nothing, nothing at all.
If i squeeze the rear flex hoses tightly and if there is no leaks at the steel lines that go to the rear brakes, then it will not matter, the pressure will not go anywhere if it doesnt leak.

And i can tell that the connections between steel and flex hoses at rear are as dry as they can ever be. I squeeze the both rear flex hoses, nothing, even a little bit doesnt change in problem that pedal will sink.

Only if i squeeze both the FRONT flex hoses the pedal is rock hard. So logically thinking, at rear there are no leaks, if there would be, pedal would still sink.

So again, where is the weak point, where pressure is lost? Only calipers it seems, but how the calipers can leak if i dont see any fluid, bubbles, air. If they leak, why they both failed at the same time. Very rarely happens.

Im not trying to be smarter than you Eric, not at all. Im just trying to think how it could / should be normally.

It must be at front something. Either the calipers or master, but master doesnt sink if i close its outlets. Not even a little bit.

Tomorrow i will try to recheck the clearance and stuff at master.
Also i will look at the brakes construction diagram how the lines run from proportioning valve and will close 1 outlet and will leave the second one connected and then i will squeeze the specific flex hose. The lines are connect in same order as they must be bleeded.

What i hope to discover with this at least at which side or what wheel the problem may be.
It should work.

Did i overheat them?! Dunno, maybe.

What if i remove them from wheels and use C clamp to hold the piston inside and then press pedal to see if it gets hard or not?

Can the master get damaged doing so?

Of course i will replace rear steel line pieces and will install new cyl. but i think that this will not solve this.

And tomorrow i will go to the store and will ask how much the new calipers will cost. One company offered me a cheap price if i give them my old ones. But its far far away from me.
I will order new calipers, but not the master, if i see that calipers are new and it still sinks. then i will order master.

[danwat1234]

OK so just so I have it clear, you recommend the silicone brake anti-seize not only obviously on the slider pins but on the shims/back of pads too, no petroleum anti-seize use at all? That’s what I plan on doing.
Thanks

[EricTheCarGuy]

[quote=”danwat1234″ post=67092]OK so just so I have it clear, you recommend the silicone brake anti-seize not only obviously on the slider pins but on the shims/back of pads too, no petroleum anti-seize use at all? That’s what I plan on doing.
Thanks[/quote]

You might want to re-watch the video because you only have part of it right.

[Veiko]

Eric

I replaced my calipers and what do you think, did this fixed the sinking pedal or not?
Ok Ok, i will not play games here.

New calipers made the pedal feel alot harder now, just like it was previously.
No sinking whatsoever.

I still have air in system, because i was in a rush to try out new calipers and just bleeded the front but even after that when i start the engine pedal is hard, just like it was before.
Now i can actually feel my brakes.

I never wanted to say that you might be wrong about calipers or something. I never told that.
Just wanted to understand the weak points in brake line, where the pressure would leak.

For me it is still hard to understand how the heck the calipers can leak so. I just cleaned the old ones so carefully, put new bushings etc in. And thought that now i have excellent brakes.
It was nothing like that, i had no brakes at all.

Now i know, i will never rebuild anything, the rebuilding did fix my calipers on my previous BMW E36, but from this problem with my Dodge Avenger i have learned that it’s pointless and wasted money. Repair kit was not very cheap. And i just wasted the money. Now i sent my old calipers far far away, they said it will go to the US somewhere, where they will be rebuilt and restored.
Whatever..
At least i got good offer if i give them my old ones.

Im still concerned about the rear steel lines between rear cylinders and their flex hoses. They are very rusty and if drive far away, can they take that pressure. If they break…
I have only 2 weeks of holidays left, i want to go somewhere. I dont have time to replace rear cylinders atm. I will bleed them. And will check for any leaks outside and if reservoir fluid level doesnt fall. I have inspection coming that i must pass.

In the meantime i will buy some new brake pipe / line or whatever they are called, the new brake line fittings for the rear and will use my double flaring tool to make new pieces to the rear.
This way it will be nice and fresh there also.

Thank you Eric for the patience and help you gave.
I repeat i didnt tell you that you are wrong about calipers, i just didnt believe that they can leak or they fail like so after “rebuilding”, lesson learned again.

Im glad it was not the master.

[EricTheCarGuy]

Glad you got it sorted out. Thanks for the updates.

[Laurence MacNeill]

So, can I use grease? Totally kidding, of course.

I was curious about why you dislike those copper washers? I never really thought about it before — but every time I’ve done a job like this on one of my cars, I’ve used whatever washers were included. Sometimes they’re copper, sometimes they’re steel…

So what’s the problem with the copper washers, if you don’t mind my asking?

Thanks,
L.

[Mike Gregory]

Hi, My 2003 expedition was pulling to the right when I hit the brakes. The faster I went, the harder it pulled. I replaced the caliper, but it still pulls to the right. I noticed that when I pulled the line from the caliper it only dripped a couple drops and that was it. I can get it to come out if I push on the brake but it did not continuously gush out. I noticed on your video that you clamped the hose, I did not have to do that. Just a couple drops and that was it. Do you think it may be a faulty hose?

[EricTheCarGuy]

[quote=”aca31″ post=73518]Hi, My 2003 expedition was pulling to the right when I hit the brakes. The faster I went, the harder it pulled. I replaced the caliper, but it still pulls to the right. I noticed that when I pulled the line from the caliper it only dripped a couple drops and that was it. I can get it to come out if I push on the brake but it did not continuously gush out. I noticed on your video that you clamped the hose, I did not have to do that. Just a couple drops and that was it. Do you think it may be a faulty hose?[/quote]

It’s quite possible. The way I test for that is to pump the pedal a bunch of times and crack the bleeder on the suspected caliper. If fluid squirts out, then it’s likely you have a brake hose problem. If it only runs out a little, then the hose is probably fine. The reason this works is because a faulty hose works like a check valve and holds in pressure.

[Mike Gregory]

I did the test and it failed. I replaced the hose and it works great now, Thanks!

[Author]

Replies