Need help with brakes.. I've searched :)

[ziljin]

Hi everyone,
I recently replaced all ball joints and front calipers/rotors and master cylinder on my '98 sport. I've been trying to bleed w/ out any luck. pedal still hits the floor. It seems like I have a steady stream coming out of the front calipers but not rears. I thought it was the mater because when pumping the brakes with the truck off it builds pressure, but holding the pedal a little more than normal pressure and the pedal starts to fall to the floor. when I start the the truck it immediately hits the floor. Does this sound like classic hcu issues? If there is air in the hcu would I not be able to get the truck even drivable?

Does anyone know if shops like midas or ntb would be able to bleed the hcu? It's the weekend, dealer is closed and need the truck for Monday :frustrate

Thanks in advance,
Jeff

 

[ziljin]

think it's possible the advance auto master cylinder is bad? Any way to be sure? Bench test or anything?

 

[ziljin]

Bump.. Any ideas?

 

[budwich]

Did you bench bleed your master cylinder before the install??? IF NOT, it is going to take a very long time for you to bleed it out. Further, if you didn't do previous mentioned, then it is likely that you have air in your ABS system which you then most "tool exercise".

 

[ziljin]

Yeah, I bench bled it before. Is it possible that it could be the booster.

 

[budwich]

OK.... let's backup a bit..... why did you do the "massive maintenance" on your system to begin with???? If there was a problem before, what was it? Is it different now? Further, I am not sure what you mean about the "no steady stream out the rears"??? Appears to ber something "funny" since in your first post, you never touched the rears??????

 

[ziljin]

Thanks for the help.. Well, the ball joints were all gone or on their way out.. Front calipers were done.. the boots and piston seals ripped... Instead of rebuild I bought loaded calipers for the fronts. Rears got new pads a couple months ago. When bleeding the brakes, they were still going to the floor once the car was turned on.. I figured it was the master which is why I changed that. Holding the pedal firmly w/ the truck off they still eventually go to the floor. I just noticed a sucking sound coming from the reservoir cap while bleeding... could this be the prob? does the reservoir have to be air tight all the time?

 

[ziljin]

the steady stream... when doing the fronts the bleeder hose fills and a steady stream of fluid comes out. the person pumping mentioned that the brakes are not falling to the floor when i open the bleeder. On the rears, I'm not getting a steady stream but the pedal falls to the floor like normal when the bleeder is opened.

 

[budwich]

Ok... that provides some more info. So prior to doing the work, although the brakes were worn, things were working "acceptably".... if I understand your "history description". It is unlikely that the parts not touched failed (possible but unlikely), so you are looking things that you did to contribute to the situation. In "normal" work, if you didn't "touch" a line, you shouldn't have to bleed it and if you do, it should be "limited" since fluid isn't going to "stream" out of it from just sitting there. This is assuming that you did a "good job" bench bleeding your master cylinder.

Back to your problem, "normal order" for "full system bleeds" is backs first then fronts (at least on fords). So you need to work on the backs some more.... checking lines and such to make sure that you haven't blown a line because that is one thing that does happen with a new cylinder is that the pressures are "better" and weaknesses will show up on old parts. As for your last post, it opens some questions about your "procedure". First, the pedal (at least on my experience of about 10 DIY jobs), the pedal rarely "falls to the floor" when you open a bleeder... you have to push the pedal down with your foot. The "proper" procedure is..... open the bleeder screw, press the pedal to the floor SLOWLY then close the bleeder, then release the pedal... repeat until the flow out at the brake in question (being bleed) is "clear". It is not clear from your statement that this procedure is being followed.

Further, now that I see your statement, addition "clarification" is needed about order.... in addition to backs, then fronts, you need to do right first then left (as in back right, back left etc).

In addition, I am not sure about the air tightness of the reservoir but I would assume its more of a "fluid tight" as opposed to an "air tight" as a "vacuum" in the reservoir would cause issues with fluid flowing into the brake line system.

 

[ziljin]

damn... I'm one of those a$$ho1es who put the calipers with the bleeders "down" or backwards... Thanks for the help.. sorry for wasted time. working fine now!

 

[budwich]

???????? but heck if things are working now, that's good.... not quite sure about the update.

 

[ziljin]

yeah, everything is working... Reversed the calipers left to right, bled the brakes, all fine again. I've done a bunch of brakes w/out any issues before.. I'll chalk it up as a brain fart? Damn what an idiot!