The Stovebolt Site Forums The Shop Area Engine Shop Vaccum brake booster oil? kit?

Can anyone recommend a source for oil for the vaccum cylinder in a hydrovac? I just scored a core from the junkyard to play with. Also how about a rebuild kit? :confused:

I need a new/rebuilt one too. Carter's had the kit listed in Cat for long time, but always outta stock. Maybe can't get anymore. I was told had to send out to rebuilder for about $275 or so for rebuild. Where do they get parts? If THEY can get them, why can't WE? Shop Manual has rebuild procedure in it, just hard to understand. Tells how it works too, I don't get it! I once had an F-600 Phord that had about same one on it. U-haul truck. Don't know how long they used them, maybe easier to find a good one from later year.
Forgot one thing, not much oil needed in there, just a few ounces to keep the leather soaked up and soft. The leather is first thing to go bad from setting.

My swedish grandmother used to say: "If you have not got it, you can not spend it." That could be the reason I go to the wrecker on a sunday afternoon to get greasy, dirty, laying under a '50 gmc headin' for the crusher to remove the old booster for $10 and change. ECI sells a brand new dual remote booster for under $250. No core charge! Plus you then get a split system (with a dual mc.) Guess I'm getting old these days worrying about 10,000# of steel bashing the Lexus. How many trucks would that cost?

Splashoil, we have a Hydrovac on our Diamond T and also wondered what type of oil to use. It is recommended that you place 1 oz. of oil in the cylinder plug every season or 10,000 miles. Our parts man told us to use Marvel's mystery oil. He said that is what they always used. Sounded kind of strange but he has been in the business since 1952 and has been on the mark on every other question we have had for him. Anyway, we followed his advice about six months ago and so far the Hydrovac is working fine. The current Hemmings has ads for rebuilds (July, pg 4384). Good luck.

Splash, have you messed with this anymore? I'm thinking of pulling mine soon. Don't really want to as I move truck time to time, but, what the hey! everything else in yard is being worked on slowly too! I have several of these units, guess I could take one of them apart first. OR, send in for core. I just thought it would be better if one being used was done, as would be less likely to be messed up as bad!

If you are going to play with it, leave the power cylinder alone. Just look over the control valve and the slave cylinder. If you go into the power cylinder, you may go down the road to end up with parts needed destroyed in teardown that you can't find. The seal and bore in the slave cylinder are most likely gremlins. Also check the vaccum lines and air cleaner lines and filter. I'm going back for more cores, to hell with Jim Carter.

Booster update: Today I pulled the Bendix booster off the '42 G-7107 1.5 ton 4x4, and found a surprize. The booster under there was the same one as the one I pulled from a '49 gmc last weekend. Caked with grime, I broke out the hot water and tsp. When I got it cleaned up, found that the slave cylinder was stainless! This is different than the '49 booster which has a carbon cylinder. Perhaps the military specified ss to avoid the pitting I expected to find. I'll try to read the brass tag # and report it here so we can check the parts catalogs. Did the Army keep some of these trucks around after the war was over?