Vac hydraulic problem

[Richard G.]

Gasket blew out on this little valve block on the Vac control block for the eagle hitch.
The gasket is a super thin material.
What should I use to make a gasket and should I use something like Indian Head Shellac?

 

[casecollectorsc]

Parchment paper?

 

[Richard G.]

Parchment paper?

It's about that thin.

 

[Joe (Wa)]

Looking at your pics, you have much cleaning to do to avoid problems after assembly.

The original factory gasket was lead. If the one you took off is not lead someone has substituted whatever you have now. I have used chart paper that is a little thicker than parchment paper and compresses better. I used a very light coat of Permatex aviation gasket both sides of gasket, let set up tacky almost dry before use. If I were doing one now I would try the newer Permatex Super High Tack Gasket Sealant, goggle it see what you think.

 

[Richard G.]

Looking at your pics, you have much cleaning to do to avoid problems after assembly.

The original factory gasket was lead. If the one you took off is not lead someone has substituted whatever you have now. I have used chart paper that is a little thicker than parchment paper and compresses better. I used a very light coat of Permatex aviation gasket both sides of gasket, let set up tacky almost dry before use. If I were doing one now I would try the newer Permatex Super High Tack Gasket Sealant, goggle it see what you think.

Thank you Joe.
When you say chart paper, do you mean the the paper that you use to put things in a file cabinet?
I will get the good Permatex sealant.

 

[Joe (Wa)]

In low pressure hydraulic systems lead was sometimes used as it compresses, fills imperfections in the mating surfaces, does not slip or blowout like a hard paper gasket.

Nautical navigation chart paper is relatively thick paper made with at least 50% cotton (sometimes called rag paper). In ships we used it in hydraulics for thin gasket material, seals/compresses and stays put even in high vibration areas.

I don't know where to find nautical chart paper as it probably isn't used much anymore. I think some bond paper is made with cotton fiber. Do a goggle search. You need a thin material that compresses b/c the mating surfaces of the cap and body are not mirror perfect.

 

[Richard G.]

In low pressure hydraulic systems lead was sometimes used as it compresses, fills imperfections in the mating surfaces, does not slip or blowout like a hard paper gasket.

Nautical navigation chart paper is relatively thick paper made with at least 50% cotton (sometimes called rag paper). In ships we used it in hydraulics for thin gasket material, seals/compresses and stays put even in high vibration areas.

I don't know where to find nautical chart paper as it probably isn't used much anymore. I think some bond paper is made with cotton fiber. Do a goggle search. You need a thin material that compresses b/c the mating surfaces of the cap and body are not mirror perfect.

Thank you Sir.
I bought something this morning that is made for hydraulic applications and I got a bottle of Permatex Super High Tack.
Gonna try to clean the surfaces with a fiber pad that won't scratch the metal.

 

[Richard G.]

Gasket blew out on this little valve block on the Vac control block for the eagle hitch.
The gasket is a super thin material.
What should I use to make a gasket and should I use something like Indian Head Shellac?

Well, I found 1/32 thick sheet lead for $10 for a square foot.
Gonna give that a try.

 

[Joe (Wa)]

Lead gaskets go on dry, no sealant, no oily finger prints, etc. I haven't ever found a torque setting for the cap bolts but I use a torque wrench on things like this. Do an initial torque, let rest for an hour or so, even overnight is ok, and do it again.

There isn't much in the manual that applies to your gasket change but you might pick up something. The leather cup piston shown was replaced with a piston with two o-ring lands sometime in 1951. The next to last pic is one of the caps I pulled probably 15-20 yrs ago. Last pic is control valve adjustment when you get it back on the tractor.

 

[Richard G.]

Lead gaskets go on dry, no sealant, no oily finger prints, etc. I haven't ever found a torque setting for the cap bolts but I use a torque wrench on things like this. Do an initial torque, let rest for an hour or so, even overnight is ok, and do it again.

There isn't much in the manual that applies to your gasket change but you might pick up something. The leather cup piston shown was replaced with a piston with two o-ring lands sometime in 1951. The next to last pic is one of the caps I pulled probably 15-20 yrs ago. Last pic is control valve adjustment when you get it back on the tractor.

Wow, thanks so much Joe.
I was going to tighten and let it sit and retighten.
I cleaned the surfaces with a scouring pad and they look good now.
Will let you know how it goes when the lead arrives.