hydro vac

[andy]

Ok, so im missing everything for the hydro-vac. After looking around and getting a price from a supplier (then pooped myself) is it a necessity to have a hydro-vac unit, or is it possible just to run manual brakes so to say?

[Outsider]

Halftracks have the rolling resistance of a brick. Most of the time when I am coming up to a corner I don't have to use my brakes anyway.

They can be operated without a hydrovac unit , but it takes more push on the pedal, slower speeds, and you need to be prepared for hard brakings situations.

Kevin Lockwood has a will fit unit that doesn't have the sticker shock of an original. So you may want to contact him to get the details.

Steve

[spec4don]

 Well it depends on how strong your leg is. The hydrovac mulitplies the braking power. You might get away with it if you plan to stay on the flat. If you run on hills or you plan to run on Public Roads that would be whole differnt story. Should you run over some thing or someone and you modified the brakes by not having the hydrovac, well hope you have good lawyer.

I'm sure that you should be able to find a used one you could get and rebuild. Check with Rod or Gary, maybe even someone here on this list might have one they could part with

Don G.

[steve-0]

The early halftracks use a linkage actuated vacuum booster to assist the brake pedal, later halftracks use an actual hydrovac.

im going to be tackling this same issue with my halftrack soon. i did try running a halftrack without a hydrovac and it hardly works at all.

the original hydrovacs where a piston type, they are not as dependable as diaphragm types so im planing on getting one of those that looks similar to the originals. this is one part that is well hidden and could use an upgrade anyways.

the m35 truck has one that looks similar and it is listed as a hydrovac but i also see it listed as airpac and air over hydraulic. so maybe someone here can verify that its a true hydrovac.
m35 around $400
edit= the m35 won't work
part numbers  p/n 8345003, 12368255, N4105H. NSN 2530000402188.
search on ebay and google




i think i will try this one, around $250
A1 cardone 518028
http://www.rockauto.com/catalog/raframecatalog.php?catalog=1&partnum=518028&a=FR1-518028-551258

[Outsider]

M35 uses air pressure as the helper so it is not a true hydrovac.

I can't find the info Kevin gave me on the "will fit" one he figured out worked. He gave me the PN of the new one and some pictures of the installation he did on one of his HT's. I will keep looking around here as I am sure it's here somewhere. And if I remember correctly it was about $200.00 for a brand spanky new one you could pick up most anywhere.

Steve

[spec4don]

Steve is right, the Deuce is an airpak so it needs air psi to operate. That is it does not operate on vacuum. The 1 1/2 ton trailers I used to pull with my 5ton had air brakes. Seemed wierd to have juice brakes on the truck and air on the trailer.

I would stick with stock unless there is a good aftermarket replacement.

Don G.

[steve-0]

people restoring cckw trucks are using aftermarket hydrovacs that i think will be our best option as well.


there are 2 types most commonly used.
http://www.cckw.org/part_number_cross.htm

piston type
A1 cardone 518028 or 51-8028
http://www.rockauto.com/catalog/raframecatalog.php?catalog=1&partnum=518028&a=FR1-518028-551258

http://www.cckw.org/forum/viewtopic.php?t=3802

diaphragm type RV2512140X   or  518030


http://www.google.com/search?q=CD518030&hl=en&client=safari&rls=en-us&tbm=shop&prmd=ivns&ei=pvaBT4XQCoigtweZlsXICg&start=10&sa=N

http://epi.hbsna.com/products/dept.asp?msi=0&dept_id=3391&parent_id=699

http://www.myvirtualpaper.com/doc/carquest/CARUQEST-Heavy-Duty-Catalog/2009091001/599.html#616

http://my.cardone.com/English/club/members/customer/ecat_brands/imageinfo.asp?PARTNUM=518030

[andy]

I ended up getting an nos hydro vac, my question is I read in one of the manuals there is suppose to be oil inside to lubricate it. What type oil, where does it go and how much?

I think mines dry ( I hope) as my power brakes dont seem to be power

Andy

[steve-0]

there is a very detailed hydrovac rebuilding manual in the list of manuals im sure its in there.
second one from the bottom

http://halftrackinfo.com/index.php?topic=993.0