Executive summary: How common would it be to have a collapsed brake hose? Bleeding was difficult in one caliper, but brakes are wearing even.


I was bleeding the brakes yesterday and my vacuum bleeder got fluid out of all calipers. However, the RR caliper was barely giving up fluid. I pulled the nipple and blasted it with brake cleaner. It didn't get much better, but I eventually got enough bad fluid out to see fresh. The bad fluid was not too terrible, an amber color.

The brake pads appear to be wearing even. The car seemed to stop ok, but I honestly only drove it 15 miles since buying. I am thinking, having read such on here, that the hose might be collapsed? It is not cracked or old looking. Car has 67k.

On the same token, The clutch slave cylinder was hardly giving up fluid, but I got it to flow clean as well. This fluid was like old motor oil in color.

I used a turkey baster to pull old fluid from the master cylinders and filled with fresh fluid before starting.

I ran out of time and was unable to check the brake pedal feel after the bleed. It was seemingly normal before so I have no reason to believe it is any different.

 

Fairly common with age.

 

Does this sound like that has occurred? Would brake pads still wear even and act normal with a partially collapsed hose?

 

If you had a bad hose one of two things would happen. Either you'd have no stopping on that wheel, or it would lock up and not release. You just might have a restriction in that caliper bleed port. If fluid is coming out on bleeding, and the brakes are OK, I would leave it alone. Otherwise, you can disconnect the line at the caliper to see what kind of flow you have. If it's good, then the "issue" is in the caliper. If the brakes work, I'd leave it.

 

Thanks for the information. I'll try disconnecting the brake line to check flow and maybe blast out the caliper with brake clean.

I need to pull the disk to see why the parking brake isn't working. There is no star wheel that I can see through the little holes. I can flush the caliper with it off the car.

I plan on getting braided lines eventually. Probably with rebuilt calipers when I replace the pads once they are worn out.

 

Each to their own I guess. I want my brakes in top notch condition at all times. I personally would not wait. Dan

 

More common in Midwest cars that the bleeder rubber plug doesn't get put back on and the bleeder itself gets gunked up. The fact that you don't see any uneven pad wear indicates it's probably a bleeder. A collapsed hose will usually tear the hell out of the pads on that wheel and create a lot of heat, making it obvious very fast there is a problem at that wheel. Worn wheel bearings or warped rotors,sticky hardware can do the same thing.Pull the bleeder and use a safety pin to make sure it's passage is open, blow out with the straw on a can of brake clean and then with compressed air, reinstall and try bleeding again. I'll bet You fluid starts gushing out. You may consider having a helper push the pedal down while you have the bleeder removed, it will usually push any crusty gunk out of the calipers bleeder hole area. can also have gunk in the caliper if the brakes weren't bled often enough so do both the above items. Brake fluid is hygroscopic and breaks down over time. For a c4 I'd consider it mandatory to bleed and flush the system at least once a year, for the cost of a bottle of brake fluid it's just good preventative maintenance. Your hoses, caliper and master cylinder seals will usually last a long time if you keep fresh fluid in the system. This is even more critical if you drive the car hard and are on/off the brakes a lot. By driving hard I mean, city driving,traffic, stop and go etc.By the way, this is probably even more critical in a stop and go daily driver than a limited use aggressively driven car that sits often. but rarely gets done. Most owners manuals give a recommended service interval for brake fluid, and they give an amended schedule for severe duty. For the c4,follow the worse case scenario maintenance schedule. Use dot 4 fluid because it has a higher boiling point. A good practice would be each spring when you pull it out of hibernation just bleed the brakes when you change the oil for the first time each season. If you track drive it consider flushing the brakes a couple times a year, heat breaks it down faster. If you can find the maintenance schedule for a taxi cab or fleet vehicle, mail delivery use.. follow it! My mom is a rural mail carrier, once I started flushing her brakes out every 90 days it stopped tearing up pads, rotors and hoses at such a high rate. If you want it to perform like a new car, keep the brake system in like new condition, that seems obvious reading it, but many people do not do that. The braking system on the 84-96 c4 is very good, the 90-96 big brake SYSTEM is even better, maintain it and it will perform like new for a long time with less maintenance costs, fluid is cheap. Keep it changed, as steel lines and hoses age they put minute amount of debris in the system, do your part to keep that debris from building up and you'll be rewarded with less overall maintenance costs and downtime.

 

dont see anything wrong with further diagnosis until u sort it out.

like the bleeder plug inspection idea.

if you remove the hose from the caliper, grab a yogurt container and put an inch of fluid in it. your old brake fluid id fine.

place the disconnected brake line below the fluid level and have a friend pump the pedal slowly-ish. you may have a blockage in your line, and you may pump it out. careful u might get a spray of fluid if pressure builds and releases when blockage releases.

If that happens, a very good plan is to replace rubber lines on all 4 corners and id expect your calipers to now bleed normally.

dont be surprised if you have a sticking caliper. These can easily be cleaned up, you can youtube vids that show you how to safely remove the caliper piston and put it back. cheers.

 

Another area to look it is the Abs pump. It has ports with little screens in it. Those get blocked. A guy posted a video a while back opening one up and showing the screen clogged. I forget the sizes but it was like a 24m wrench and a really big allan key or maybe a torx. Once you open the ports it was really easy to remove the screen, clean and tighten. You might need one of those sets of different size o-rings too. I have a spare ABS pump that I will open up one day. Its on the to do list...

 

Amen to that, I can tolerate many old, sub par, less than perfect things in an automobile, but brakes that are less than perfect are not one of them. Another no go thing is any sort of fluid leak. As a younger man I blew up a good engine due to a slightly leaky heater hose that I managed to keep putting off, logic said too it off every other day, keep an eye on it. By allowing air pockets into the cooling system it blew head gasket, warped the head and block. Basically making it cheaper to just purchase a used engine and replace it. Live and learn. Now days if I have to rent a car to get to work due to car needing repairs so be it. Murphy's law is in full effect, especially with the 39-25 year old c4. I figure the car doesn't stand half a chance of survival if I am not 110% diligent in maintaining it. Just saying. But to the op, these cars are not getting younger, body parts have been discontinued for over a decade now, used parts are in short supply. Don't take chances with the brakes, you'd hate yourself if it caused a fender bender and 5-6 grand in body damage.