Can't Bleed My Brakes

[mistermeena]

new development: I gave up on the front left side and thought I'd try bleeding the front right just for laughs, and it worked. Front right seems to bleed fine and pumps good clean fluid out. So hopefully this proves my master is fine? And I'm thinking this suggests a blockage in the lines to the front left? If that's the case how do I deal with it can I remove the rubber line to left caliper and metal line from the master (to front left) and blow compressed air down it?

[PN-Mad]

Figure out if it's a blocked line or blocked caliper first. Take the line off the caliper and gently see if you can get fluid through. Then you isolate either line or caliper

Good work!

[Daleo]

new development: I gave up on the front left side and thought I'd try bleeding the front right just for laughs, and it worked. Front right seems to bleed fine and pumps good clean fluid out. So hopefully this proves my master is fine? And I'm thinking this suggests a blockage in the lines to the front left? If that's the case how do I deal with it can I remove the rubber line to left caliper and metal line from the master (to front left) and blow compressed air down it?

As PN-Mad said; split the line first.

Don't forget; you can generate well over 2000psi with the brake pedal and booster.

If that doesn't clear a blockage; compressed air certainly wont.

[89CAL]

Yeah but blowing the opposite way through the line might.

I'd suggest that if you have narrowed it down to one caliper then take it off and start from there. Maybe connect it to the other side and see if you can get it to work with the brake line on that side. That will completely rule out caliper. then you can mess around with the brake line.

It will mean starting from scratch pretty much but re-bleeding brakes is not such a big deal compared to the trouble you have had so far lol

[mad082]

It's pretty safe to say that it's going to be the line. He's already stated a few times that he tried bleeding the system on the dodgy side with the caliper off and it wasn't pumping much fluid out.

I'd start by looking for any kinks in the metal line. I've driven a car with a kinked brake line and you could turn corners by taking your hands of the steering wheel and just jumping on the brakes, lol.

Trying to blow some air back up the line may help if there is a blockage at the start of the line. If there is though, you'd want to then blow out the other line too so it doesn't get blocked. Do the fronts have one line out of the master cylinder that then splits, or is it 2 straight out of the master? Cause if it's 2 then the blockage may be in the master still.

[mistermeena]

I had already removed the rubber line from the caliper and found that I had the same problem at the line so I took that to mean the problem was the line not the caliper.

Anyway I got stuck into it again today and strangely enough, the front left (the problem one) bled fine first go through the nipple. That worries me a bit, because really only clean fluid and air came out so I'm not sure if I've cleared a blockage or just dislodged it to somewhere else lol. After that I bled the front right again no problems, then bled the master and got a little air through that but it came good after a few pumps.

I then went to the back left to start the whole process again and the back left went fine no air came out. The back right keeps giving me fluid and then air for some reason, even after we did it more than 20 times or so. Anyway it got dark so I'll have another crack at that one tomorrow and hopefully it gets there eventually.

[mistermeena]

Also someone suggested earlier to try this with the engine running so should I be doing that? The reason I havent tried that already is because the battery is dead and it's a bit of pain to jumpstart it where it's currently parked - I'd probably have to put it back on the ground and roll it back or maybe get a second set of jumper leads to extend the length. Having said that if having the car running will have a significant impact then I'll do it.

Appreciate all the help guys I'm determined to have brakes!

[mistermeena]

Well I'm stumped again. The problem on the front left seems to have resolved itself but now I keep getting air through the rear right. I put almost a whole bottle of fluid through the resi and still get big bubbles.

This is really starting to get me down :|

Edited April 30, 2014 by mistermeena

[warps]

I thought I responded to this yesterday? Must've hit the back button instead of submit

The air coming out of your caliper is most likely air from the rubber drain hose you're using. Is the fluid draining out of the hose and getting displaced by air (not the brake hose, but drain hose you're using to drain the excess fluid into a container). I assume you're attaching a drain hose to the nipple and running the spent fluid into a jar / bottle of some sort. if you remove the hose from the nipple between bleeds, the fluid drains out and it fills with air (if it's a small diameter hose, and you don't disconnect from the nipple, then the fluid stays in the hose due to "suction"). I got caught this way on a Datto 1600 many moons ago.

Make sure this isn't what's happening. I find it highly unlikely that you are sucking air into the brake system. If you had a leak that big, then it would be pissing fluid out under pressure.

Also, you don't need the engine running to bleed brakes. Won't make a difference to your needs. How do you think race cars without a brake booster effectively bleed brakes (given some of them will bleed brakes after every session)

[jiffo]

If it's making air and presuming you're keeping the reservoir topped up, using hose, bottle etc properly, you have a master cylinder problem.

[mistermeena]

Yeah the procedure is correct so I guess I'll have to start looking for a new master

Warps: What I'm getting is maybe 2-3cm of fluid in the drain hose, then a big(ish) bubble, then another 2-3 cm of fluid. And it just goes on like that forever. I've been over all the lines there's no fluid leaking out anywhere and all the hoses and nipples are tight. Also, I've still got no pedal feel it goes right to the floor. If I pump the pedal with the nipple closed it goes slightly harder and stops at maybe 3/4 to the floor.

I ended up running the car yesterday and I noticed that the idle drops slightly when I press the brake. Is this likely to be related to my problem? Does it suggest a faulty brake booster or master? It didn't have this problem before I changed the calipers

Edited May 1, 2014 by mistermeena

[mistermeena]

So i did the gravity bleed thing this morning and I now have working brakes, with seemingly good pedal feel. I dont know wtf was happening there, but I'll be getting my mechanic to check the brakes out for me anyway.

cheers guys suggestions were very helpful.

[warps]

Sounds like a good idea. If there is a problem, it's better to get an expert to check it out properly.