I recently upgraded my calipers to single piston Legend/Prelude/ITR units with AEM pads, Brembo '91 EX rotors, SS lines, a 15/16" '91 Prelude master cylinder finished off with a full fluid flush with Motul RBF 600. First time around i didn't do a good enough job bench bleeding the MC and the left caliper's bleeder did not spit out any fluid during bleeding, just air (regular old 2 person manual bleeding) Realizing my mistake (or so I thought) I bought the bench bleed kit and re-bled the MC correctly. Now the left side is squirting fresh Motul juice and no air bubbles but now the right side is barely putting any fluid out. What could cause uneven pressure between sides like this? If it were different from front to back I'd suspect something with the prop. valve but this has got me fairly stumped. Especially because the good pressure went from one side to the other after bench bleeding (ruling out a seized caliper, blocked bleeder, or anything else specific to one side or the other). Any intelligent suggestions would be greatly appreciated!

 

I should certainly mention that this is all on an '89 DX Wagon.

 

your brake lines aren't being pinched are they? have you tired blowing compressed air through the lines to clear them out?

 

proportioning valve I would think. depends how the system is split

 

No, lines aren't visibly pinched but I do not have a compressor to blow the lines out and check for blockages. I wouldn't think that's the case though because I've had good pressure on both sides, just not at the same time. And I doubt it's the prop valve either due to the fact that I had normal braking before the swap. I have a feeling that I just have some air trapped in the system and its compressing during bleeding and not allowing fluid to skeet out on that side.

 

In what order are you bleeding the brakes? Sounds like you just may need to do it in the correct order and do it a few times around the car, mine spit bubbles for a good 2 laps around the car after doing a brake line and M/C swap, I ended going around the car 4-5 times before I felt everything was out.

 

I have used vacuum bleeders with good results. If you get a good one .....

 

I'm using Honda's sequence. RR, LR, RF, LF. both rears are still spitting out the 20+ year old green Honda fluid, but both are also bleeding just fine. No troubles until I get up front. I'd like to vacuum bleed them but I don't have a vac. bleeder and would prefer not to buy one. Im going to try the clear hose/bottle 1/2 full of fluid method next. I have a friend who worked as a tech for Honda for almost as long as I've been alive and that was his suggestion. This a really simple swap and nowhere near my first one. I'm sure its something simple at this point. At least this trouble has convinced me to overhaul the rear drums while I have air in the system already! haha

 

Ok this might be a simple question,, you sure you opened the bleeder far enuff? Might be a flap in the brake line take brake line off and blow through ..

 

 

And yeah I'm positive it was open the whole way. I even tried opening it further and further each time because I thought the same thing. Then I stole some bleeders out of a spare set of the same calipers and it had the same result.

 

are the calipers new or used? if they're used take the bleeder out and inspect the hole. you may need to clean out the bleeder if there was no rubber caps on them.

 

Sorry for the delay. I've been busy with the holiday, packing to move and work. However, I got a chance to really bleed the whole system today and I have a new development. I got a bunch of air out of the FRONT LEFT and RIGHT REAR and actually have some pedal now. The bad thing is that I'm still not getting good pressure on the other two, and more importantly the pedal isn't sinking the whole way when the bleeders are opened on those two(FRONT RIGHT, LEFT REAR). Does anyone know if those two have something in common that the other corners don't share? If there was an obstruction in one corner I don't think it would affect the opposite corner in the same way but if there's a line that's common to those two and not the others that would make sense. Sorry if that's complicated to read I'm not sure how to simplify any more.