DOT 5 leaking from lower plunger on disk brake distribution block

[mseagle]

I need your guys help.  I really don't know what do at this point.  I'm on my third Inline Tubing '71 disk brake distribution block.  The entire braking system is brand new.  I'm running DOT 5 brake fluid and it keeps leaking out of the lower plunger boot on  the disk brake distribution block.  I called Inline Tubing and they said there's really no good option.  The parts are made overseas and the DOT 5 is getting around the internal o-rings.  Now I have air in my lines.  I'm not sure what to do.  Buy another distribution block and bleed brakes and see what happens?  The entire car is an OEM restoration and I don't want to go the aftermarket route.

I see guys on the forum running the exact same set up and not having any issues.  I really could use some help!

Thanks,

Mark

[mseagle]

Here's the setup I'm running from Inline Tubing.

[Cudakiller70]

Not familiar with that exact part. I'm wondering if the brake fluid is not compatible with the seals they are using. There is a place online who sells rebuild kits, I think they may use a higher quality o ring or seal boot or whatever it is part that's leaking.

[Cudakiller70]

This is the place I've used twice
https://www.musclecarresearch.com/valve-rebuild-kh-multi-prop

[6bblgt]

stainless steel brake lines?

sometimes the harder stainless steel lines are difficult to seat/seal on the brass block ( it is the line, not the block?)

[mseagle]

No I'm using regular OEM steel lines (all new), not stainless.  It is leaking out the bottom of the rubber boot that surrounds the plunger on the secondary small block.  If the car sits for awhile I will have a small circle of brake fluid on the floor.  When I pull the car out and hit the brakes, a nice size little puddle shoots out the bottom of the boot. This has happened on three separate block from Inline Tubing.   They told me to get rid of the 71 style second block and go with a more 70 look.  I really don't want to do that either.  I might try the rebuild kit and see what happens.  Thanks for the link!

[PatO]

I purchased that unit also. Leaked in 3 places. Found brass shavings in the internals. 

I got it down to 1 fitting leaking and then gave up. 

For what it's worth I bought a wilwood unit for now. No leaks.   I'll search for a vintage disc/drum unit this winter to see if I can rebuild.

[JonH]

Get rid of the Dot 5 fluid. It is attacking the rubber parts in the block. I would flush the system and go with Dot 3 or 4 if it was me...

[mopar jack]

I had the same issue and my friend 1933 dodge also had this problem. We both tried a couple of new replacements and they all leaked  and yes we use dot 5. 1933 dodge had his valve brazed at the bottom to stop the leak and maintain a stock appearance on his T/A. I removed mine and istalled a tee. That part is what some call the hold off valve to prevent wheel lock up on icy roads. I don't think I will worry about that.

[GoodysGotaCuda]

Get rid of the Dot 5 fluid. It is attacking the rubber parts in the block. I would flush the system and go with Dot 3 or 4 if it was me...

The DOT 5 isn't "attacking" anything, in my opinion. It's pretty docile stuff, it sounds like a quality issue on the valve side.


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[RUNCHARGER]

I agree: I've used DOT5 on the last few cars with 45 year old Mopar valves with no issue. It is a chinese valve quality issue. As usual.

[mseagle]

I appreciate all the help guys.  I just ordered another one from Dr. Diff from another manufacturer.  I'm sure its also made in a China but hey I might get lucky this time.  If this doesn't work I guess I'm going to have to find a NOS MOPAR one.  The DOT 5 is nice on the paint which is why I run it. 

[mopar jack]

I decided to repair my metering valve and take out the tee one last time. I went to the link above and found the part needed. The seal appears more pliable than the one that leaked and it's been two days and no leak at the valve. Still working on the tube fittings that weep. This link will take you to the rebuild article. https://www.musclecarresearch.com/content/1970-71-mopar-metering-valve-rebuild 

[Headjam]

@mseagle This old post pretty well sums up my situation. New steel lines, new distribution block, DOT 5, and new metering block. 1970 Challenger. CANNOT stop the fluid from leaking out under the distribution/metering blocks. Everything is tight.

Any new ideas or recommendations?

[MoparLeo]

Don't spill brake fluid. How often do you even mess with fluid ? Usually only when you do a brake service.

https://centricparts.com/getmedia/aaff9ed4-541c-45a4-abc2-a3b667385808/Centric_and_APC_Technical_Whitepaper_D1-Brake-Fluid-1A_8-2018.pdf