Alfa Romeo Forums banner

1 - 20 of 45 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter · #1 ·
I will be tackling my sticky brake problem tomorrow (along with an ignition problem) and was wondering about the best way to analyze the brake issue. I believe that the front right and rear left brakes are not retracting completely and are rubbing on the rotors. I have done extensive searching on the forum here and have narrowed it down to two options: either the pistons are stuck and the calipers need to be rebuilt or the lines are clogged and need to be replaced/flushed. (both of which I am confident in doing)

Is there an effective way to narrow down which one of these problems I am experiencing? Keep in mind I have never done any extensive brake system repairs and would like to expand my knowledge on the subject. I will post pictures as I go tomorrow. I realize this is a very common and greatly discussed problem, but any input would be greatly appreciated.

- Scott
 

·
Premium Member
Joined
·
974 Posts
I recently brought the brakes on a '71 GTV back from being very sticky. My input is do it all at once. You are going to put so much effort into just the bleeding part of the job that you might as well do it all. In my case I decided to rebuild the calipers myself, replace the flexible lines, keep the hard lines and although I wasn't planning on it I replaced the master. My logic was I could rebuild the master but I read a lot about failed masters after rebuilds, and some that never really worked and so for the cost difference I decided to replace that part, especially since it is the single point of failure. Unless you are very lucky, you are going to bleed the lines until you've gone through 2 or 3 big cans of fluid. One thing that sounded good that I didn't do but which I will next time, was to bleed the master on the bench first.

Good luck and I hope others who have more experience chime in here...
 

·
Registered
Joined
·
437 Posts
I'm with cabikefreak.
When I had the brakes problem, I replaced all rubber hoses and rebuilt the calipers and the master cylander.
One time work and you know it is good for a long time.
Saar.

edit: do not replace/rebuild only one side of the brakes, it should be done in pairs.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #4 · (Edited)
OK, I will order a rebuild kit for each caliper and new hoses and pads all around. How would I know of the Master needs a rebuild or not? The two remaining calipers appear to be working normally. Would this indicate that the master is OK? Also, this being my first Alfa, I am not yet 100% with the ins and outs of this vehicle. IAP lists hoses for the front and then one "rear center." Is there only one rubber hose on the rear end? I am away from the car until tomorrow and will probably be able to answer my own question by then, but just wondering for now.

:edit: Nevermind, I did some research and answered my own foolish question. Will update tomorrow.
 

·
Premium Member
Joined
·
974 Posts
Regarding the master...

In hydraulic systems when you rebuild one end and not the other a lot of times you will have problems. For example when you rebuild or replace the master and don't do anything with the calipers, the additional pressure you generate may finish off the old seals in the pistons. But if you do the calipers and not the master, I'll bet you soon expose the weakness in the master that is most likely there because you'll be moving more fluid back and forth now that the caliper pistons are unstuck. Over a long period of time the piston and seals in the master get used to certain start and stop positions and when you all of a sudden start going outside that range, the old seals often give way. And sometimes just replacing the fluid and going through so many cycles with the master during the bleeding process you'll finish off old seals in the master anyway. That's why unless you just can't swing the additional dollars and have to drive the car, it is best to do both ends.

I'm not familiar with your year but if it has a balancer between the front and rear it may need cleaning, if not a seal replacement as well.
 

·
Registered
Joined
·
3,585 Posts
First maybe your postulate is incomplete, you could have pads that are hanging up on the guide pins and/or the rotors and/or pads could so worn as to impede proper operation. I'd go back to the begining to diagnois and solve rather than blindly rebuilding compenents that might not adress the problem and inadvertently might lead to other complications. New pads, measuring the rotors to make sure they are correct thickness, replace the three flex lines with braided steel, then flush and bleed the brakes. At that point you have a good baseline to start from.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #7 · (Edited)
Roger,

You are correct. I have been away from the car and have not been able to look at the brakes physically. I am on my way to the car right now and will be able to better diagnose the problem once there. I wanted to gain insight on what others had done to solve this problem. I will start with the basics before doing anything drastic. I will post some pictures if I come across anything unusual. What should I use as an acceptable rotor thickness? Thanks
 

·
Registered
Joined
·
318 Posts
I recently brought the brakes on a '71 GTV back from being very sticky. My input is do it all at once. You are going to put so much effort into just the bleeding part of the job that you might as well do it all. In my case I decided to rebuild the calipers myself, replace the flexible lines, keep the hard lines and although I wasn't planning on it I replaced the master. My logic was I could rebuild the master but I read a lot about failed masters after rebuilds, and some that never really worked and so for the cost difference I decided to replace that part, especially since it is the single point of failure. Unless you are very lucky, you are going to bleed the lines until you've gone through 2 or 3 big cans of fluid. One thing that sounded good that I didn't do but which I will next time, was to bleed the master on the bench first.

Good luck and I hope others who have more experience chime in here...
I second that. Yesterday I removed all four calipers for rebuilding and I'm ordering a new master from IAP. I'm also going to replace the crusty 40 year old hard lines as well.

The master cylinder is $76.95 from IAP which is cheaper than rebuilding it; and the hard line kit is $77.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #11 ·
I have taken pictures of all four brakes. I will post them up within the next few hours so you all can visually see what I'm talking about. 3 out of 4 calipers are rubbing on the rotors with the back left being the worst. Both front calipers are rubbing as well. I haven't removed the calipers yet but I would like your preliminary diagnosis.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #12 ·
OK, I'll start with the worst one first. Rear left brake. Won't spin freely and creates a grinding/scraping noise when it does move. There are several deep grooves in the rotor, so I think it needs replacing. This brake was extremely hot after a 5 minute drive.
 

Attachments

·
Registered
Joined
·
71 Posts
Discussion Starter · #15 ·
The front right brake was not able to move freely, although there were no grooves or unusual wear on the rotor. It took some force to move it but it did so without any grinding/scraping noise. This caliper held tighter on the rotor than the front right did.
 

Attachments

·
Administrator
Joined
·
17,811 Posts
Rebuild the calipers, replace the master cylinder, replace the flex lines and inspect the hard lines - replacing if any question. Replace or have the deeply grooved rotors turned. Brakes are a vital part of safe driving - a car that won't start is a nuisance. A car that won't stop is dangerous!
 

·
Registered
Joined
·
1,748 Posts
Looks like siezed pistons in the caliper to me. Try to use a big screwdriver to push them back into the bores before taking them off. Rebuild all 4 and install new pads and rotors where needed. Do you have a micrometer to measure the thickness of the good ones??

Repack the front bearings while you are in there. New wheel bearing seals too.

New rubber hoses are cheap and should be replaced.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #20 · (Edited)
I was leaning towards seized pistons as well. I do have a micrometer as well.

Roger,

I agree with you that all of the pads/rotors are past their wear limit and need to be replaced/turned, but if that was the only issue shouldn't the pads be releasing from the rotors despite being past the wear limit? Not trying to stir up conflict, just wondering if there is something I am missing.

Either way IAP is closed for the weekend so I have a day to decide what I have to order. I was leaning towards rebuilding all of the calipers, replacing flex lines and the MC. New pads and turned/replaced rotors.

Would there be any desire for me to provide a write-up of the whole process?
 
1 - 20 of 45 Posts
Top