[MilanoItalia]

Hi All,

I just finish rebuilding my calipers, installed, and then road tested. I came back to check the calipers and notice the bleed valves are seeping not at the tips but at the threads. There is enough seeping to form a one or two drop line down the caliper. This is happening on both sides so the question is what is causing the seeping? When I screwed in the new OEM bleeders they were just a tad loose and not firm and I torque them down carefully so I don't strip it. I made sure everything was clean so the valve can seat properly but it is still seeping.

Do I need a sealant around the threads?

Thanks in advance.

 

[Alfar7]

Bleed screws

No, the screws are not seated. Use the old ones or tighten these.

 

[MilanoItalia]

Thanks - I've tighten them down pretty tight. Do you know the torque specs? I just don't want to strip them on the aluminum side

 

[161qv]

some times a new bleeder valve may have a diffrent pitch you may half to bed them in.

 

[MALDI]

You may consider using the high temperature thread sealant used with Speed Bleeders:

Sealant

I have not used it myself but it is designed to solve the problems you are having.

 

[MilanoItalia]

Thanks everyone. Looks like the speedbleeder sealant is the answer.

 

[AR4me]

Looks like the speedbleeder sealant is the answer.

Shouldn't be necessary, as suggested above I would use the old bleeder screws. In the past I have bought rebuild calipers and have had to use the old bleeder screws - maybe the rebuilder was snoozing...
Jes

 

[Gubi]

You may consider using the high temperature thread sealant used with Speed Bleeders:

I have not used it myself but it is designed to solve the problems you are having.

Well, no. The problem the sealant is supposed to fix is air leakage around the threads during bleeding (when the bleeder is slightly screwed out). When the bleeder is screwed in, the end of the bleeder should seal securely and there should be no leakage through the threads.

Maybe the bleeder may not be screwed tight enough (though usually it doesn't take much...I'm pretty paranoid about snapping them off) or the wrong size?

 

[75evo]

How does the seat of the bleeder screw look like? Or maybe the seat on the caliper side is chipped? Or the new bleeder screws' seats are not properly machined?

 

[NMMilano]

Get the bleeder and seat very clean, put some Prussian Blue (a machinists die that Permatex and others supply) on the bleeder where it should seat,then screw the bleeder in and tighten lightly, remove the bleeder and you will be able to see where contact is/isn't being made. I have never used a sealer on bleeder screws.

 

[MilanoItalia]

Update: I torque down the bleeders just a tad and then went for a drive, came back and checked. Passenger side is good no leaks. Drivers side still has a very very slight seep. I'm going to take the bleed screw out and check the seat area on the caliper side, clean out and re-seat.

Question: when screwing in the bleeder is it loose or does it have some thread tension?

Does anyone have the torque specs for the bleeder screw? I'm really nervous about striping the aluminum threads.

 

[MALDI]

Well, no. The problem the sealant is supposed to fix is air leakage around the threads during bleeding (when the bleeder is slightly screwed out).

While your statement is correct, and I didn't express myself clearly before, the larger point is that it is a high-temperature, brake-fluid-compatible sealant. Although it shouldn't be necessary, it may stop the slight amount of weeping that is the issue here.

I solved this problem for my car by buying bleed screws from a different supplier. Either the caliper bleed-screw seats or the bleed screws themselves (or both) are not machined to very high tolerances so they may have different seat angles. You may have to mix and match bleed screws with calipers to find the best fit.