The Stovebolt Site Forums The Parking Lot Big Bolts Bendix Hydrovac Booster Question

Hi All,

I thought I'd put this question in the bigbolts section since hydroboosters usually are only found on 1 ton and bigger trucks.

I have been searching autozone earlier and noticed that they carry 2 different hydroboosters for our trucks. The part numbers are 51-8028 and 51-8062. They label them as 51-8028 being a hydrobooster with master cylinder hydrovac and 51-8062 as hydrobooster without master cylinder hydrovac.

My question is, what exactly is the difference if anone knows? I'm assuming one has an extra feature and the other doesn't, but I'm not sure. If there is a difference in operation, does anybody know the pros and cons?

I'm sure somebody on here will know, Thanks,
54Monster

So are you trying to add a booster or replace an existing hydrovac. If you want to replace an existing hydrovac, I would go to someone who knows something about them. I would not consider Autozone as someone who would know anything about almost 60 year old brakes.

I appreciate your response. I have a working unit under my 2ton. I was just noticing that there seems to be 2 different types being offered and was wondering what the differences between the 2 units are, if any.

Thanks,
54Monster

Hy guys, this may just be a terminology thing, but a hydrobooster is a booster that uses hydraulic pressure from a power steering pump to accomplish the boost. The hydrovac uses engine created vacuum to provide the boost. 54Monster, please remember to tell us what year and size of truck you're asking questions about, I assume it's a 54

Bendix made several different part numbers of the same basic hydrovac. They will work in the place of each other, but will require plumbing changes. It is much easier to identify the one you have and replace like for like. If yours is working, I wouldn't worry about it.