Out of Ideas (World's Longest Brake Job) (Page 4/5)
Doggo APR 16, 06:21 PM

quote
Originally posted by cartercarbaficionado:

thats really weird. i guess try the old hoses? does fluid reach the hard line side of the rubber hose fine?



Yeah like even just loosening the soft line at the top end is enough to get fluid dripping from the hard line fitting. And then if you take the banjo bolt out and let the hose dangle it’ll start to drip fluid pretty good.

[This message has been edited by Doggo (edited 04-16-2025).]

Filben APR 16, 06:35 PM

quote
Originally posted by Doggo:

Soooo… the “new” proportioning valve has not fixed my issue. So we’re back to the basic question: why would fluid not be reaching the front calipers? Consistently that is. It should have everything it needs, new hoses, new calipers, clear lines, new bench bled mc, pushrod isn’t too long, clear prop. valve. It just won’t push it!



I would pull all the lines and recheck them for flow. I would also confirm the calipers are not clogged up somehow. I would pull each line one at a time starting at the calipers and try and pull fluid through, keep doing that all the way until you find out where the fluid is not making it through and that will be the problem(I suspect the master cylinder is just being **** , you can get 2-3 dead parts in a row sometimes). Does it bench bleed?
Doggo APR 16, 06:53 PM

quote
Originally posted by Filben:

Does it bench bleed?



Yeah, I use the little plastic fittings that screw into the line holes with little hoses looping back up into the reservoir. Very slowly depressing the brake pedal does cause fluid and bubbles to flow back into the reservoir. I don’t have a vice (I have a vice but no surface to affix it to. My “workbench” is two pieces of plywood on a set of sawhorses) so I have to do it on the car . But we make sure the master is level while “bench” bleeding.

[This message has been edited by Doggo (edited 04-16-2025).]

cartercarbaficionado APR 16, 09:23 PM

quote
Originally posted by Doggo:


Yeah like even just loosening the soft line at the top end is enough to get fluid dripping from the hard line fitting. And then if you take the banjo bolt out and let the hose dangle it’ll start to drip fluid pretty good.



remove the bleeders from your calipers and let it drip fill them til it runs out. it seems like your calipers might just be full of crap or manufacturing debris.
personally i havent had to deal with remans or new stuff because im so much of a cheapskate i rebuild them myself for the 5 dollars it costs

[This message has been edited by cartercarbaficionado (edited 04-16-2025).]

Doggo APR 16, 11:17 PM
I also had picked up another OEM master cylinder from the fellow who gave me the valve. After disassembling it, it's clear that the internal seals are fine, however the seals that seat the reservoir are rotted to all get-out. Can I put it on the car like this or will problems arise from the outside seals? It doesn't even look like they do anything since the plastic of the reservoir goes way down into the holes. None of this would matter if I could just get my hands on a rebuild kit and change them, but it doesn't appear that anyone makes them anymore.
cartercarbaficionado APR 17, 12:57 AM

quote
Originally posted by Doggo:

I also had picked up another OEM master cylinder from the fellow who gave me the valve. After disassembling it, it's clear that the internal seals are fine, however the seals that seat the reservoir are rotted to all get-out. Can I put it on the car like this or will problems arise from the outside seals? It doesn't even look like they do anything since the plastic of the reservoir goes way down into the holes. None of this would matter if I could just get my hands on a rebuild kit and change them, but it doesn't appear that anyone makes them anymore.


it should be fine? i tend to not remove the reservoirs unless i have to, i believe the s10 masters use the same seals if you can find a junkyard one or use orings since its just holding back the force of gravity on the fluid
edit:if you have a bunch of the new ones just steal the seals from of those

[This message has been edited by cartercarbaficionado (edited 04-17-2025).]

Backroadgee APR 23, 12:03 AM
Did you measure the push rod length in relation to the mounting surface to be sure the piston is not being pushed slightly.
IMSA GT APR 23, 08:27 PM

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Originally posted by Dave Deerson:

2. Did you measure the push rod length in relation to the mounting surface to be sure the piston is not being pushed slightly





quote
Originally posted by Backroadgee:

Did you measure the push rod length in relation to the mounting surface to be sure the piston is not being pushed slightly.



Interesting.
cartercarbaficionado APR 23, 08:42 PM

quote
Originally posted by IMSA GT:


Interesting.



quote
Originally posted by Doggo:

UPDATE the pushrod length was fine. I’ve managed to source another proportioning valve (thanks Carter for the hookup) so we’ll see where that goes. Will keep you posted.



i wish they would look through the thread right imsa?, im pretty sure doggo is suffering from a poorly rebuild caliper or extremely bad luck with parts at this point. ill let him know when i rip into the gts brakes throughly

[This message has been edited by cartercarbaficionado (edited 04-23-2025).]

Doggo APR 25, 07:15 PM

quote
Originally posted by cartercarbaficionado:


i wish they would look through the thread right imsa?, im pretty sure doggo is suffering from a poorly rebuild caliper or extremely bad luck with parts at this point. ill let him know when i rip into the gts brakes throughly




The calipers are brand new cast ones from china. When I get some time (probably this weekend) I’m gonna put that OEM master I got from Lucas back together and try it out. If that doesn’t work I’m gonna try reinstalling old calipers.