Need a little brake advice

[Hurseyc]

I started with working manual disc/drum brakes and went to a vacuum power setup and having some problems. I've been reading a lot of the brake conversion threads and am just looking for some thoughts.

BTW - Front is the Chevy disc conversion.

After initial install of the power setup I couldn't get them bled and couldn't get any pedal. I figured out the rod (into the MC from the booster) was adjusted out too far and the MC was never "releasing". Once I backed that off, it seems to have bled well and I instantly got some pedal.

So at this point the brakes are pretty good but not great, and each time I take it out there's LOTS of brake fluid shooting out of the MC. Looks like from the front which on my MC is the bigger side and going to the front brakes.

When I say good, I mean the effort is good and it stops okay but I feel like the pedal goes down further than I'd like and I can hit the floor without locking up either front or back.

I've read that often the cap needs to be hose clamped on to stop the leaking. It looks like the cap is seated correctly and the bales are tight. I'm wondering if I need to try the hose clamps or if it sounds like there's still too much back pressure and it's squirting out.

Any chance I need to adjust that rod any more or once it's working is it pretty much a done deal?

BTW - Have the GM style prop valve and recently had to replace the plunger thing due to a leak so I'm not 100% sure that thing is working correctly.

I'm considering going to a setup where it's direct to the front and a manual prop valve to the back but I'd like to have this sorted out before I go making huge changes and cause more problems.

Anyway, thanks for reading and let me know what you guys think.

Chris

 

[Blue Bastard]

I had a leaking problem with tthe m/c cap. I used a litle piece of hose on the bail to create more pressure and it stoped leaking after a little bit. almost like the seal needed time to seat.

as far as the rest of the concerns i will defer to the experts as it is not one of my strong points.....

 

[Hurseyc]

I'm not opposed to smashing down and securing the cap but I don't want to mask a different problem. Thanks for the input.

 

[savage]

Mine was leaking, tried to buy new cap, still leaked. A friend said to put the old MC in a vice, then take my cap with a seal under it and place it on the MC in the vice, take a small hammer and tap all the way around the edges. I put it back on and had no more leaking. I know the rod needs to be adjusted were their is very little movement. Mine is adjusted were it just touches, were it at full release.

 

[DirtDonk]

So at this point the brakes are pretty good but not great, and each time I take it out there's LOTS of brake fluid shooting out of the MC. Looks like from the front which on my MC is the bigger side and going to the front brakes.

While this can be common and almost "normal" it's not correct. Even a properly working system will squirt a little geyser when you release the pedal. Your excess may be indicative of the amount of stroke you're putting it through by having such a soft pedal.

When I say good, I mean the effort is good and it stops okay but I feel like the pedal goes down further than I'd like and I can hit the floor without locking up either front or back.

Not good. Needs some more adjustment/tweaking of the components it sounds like.
Have you verified that the front calipers are not hitting the knuckles where you clearanced them with a grinder?
And you may have to go back in and re-adjust all the rods. But first pull the master off again and make sure that the gap between the tip of the rod and the back of the piston is very minimal. Just a smidge before they touch. Maybe 1/64th of an inch?

I've read that often the cap needs to be hose clamped on to stop the leaking. It looks like the cap is seated correctly and the bales are tight. I'm wondering if I need to try the hose clamps or if it sounds like there's still too much back pressure and it's squirting out.

Very possible. Save the clamps for after all the other tweaks are made. With luck you won't need them. Crossing fingers...

Any chance I need to adjust that rod any more or once it's working is it pretty much a done deal?

Sounds like a distinct possibility.
The booster-to-master rod. The bellcrank linkage. And the pedal to bracket rod. All might need some setting. Did you follow any instructions carefully?
Are your calipers mounted with the bleeders pointing up, or at least in the upper end of the caliper? This is critical to a good bleed.

BTW - Have the GM style prop valve and recently had to replace the plunger thing due to a leak so I'm not 100% sure that thing is working correctly.

May be letting air in, or maybe you just need to pull it out (the pin only, not the valve) during your bleeding exercises?
That's a delay valve (forget what they really call it these days) and does effect low pressure settings in the front circuit (this is for the front on yours, correct?) so depending on your bleeding method, could give you some trouble unless you can pull it and hold it out. Either with the help of another bleeder/person or by grabbing it with some small vise-grip pliers to hold it out. When pushing on the pedal you can usually see it move outward.

I'm considering going to a setup where it's direct to the front and a manual prop valve to the back but I'd like to have this sorted out before I go making huge changes and cause more problems.

Good idea for Broncos that are no longer balanced even remotely like they were originally, but here again, you should not have to if all else is working. Theoretically...

Good luck.

Paul