Desperately seeking Hydro Vac

[Vanessa]

I'm at the end of a brake rebuild, and the mechanic can't find a set of Hydro Vac Boosters for my 1970 D22 Winnie (M300 Dodge chassis). I've gotta get on the road before the snow hits... any leads???

[DaveVA78Chieftain]

When looking for parts in that year range, I am reasonably certain the your M300 is also known as a P300.  MAny times you can find listing for P300 when M300 is not listed

The Hydrovac unit was used on the 72-73 M375 chassis
The C-490G Midland Ross unit was used on the 1969-71 Dodge Class A M300 (Early) chassis
The Master Vac unit was used on 1972-73 Dodge Class A M300 (Late) chassis

Use the pictures on those pages to ID the booster you need.

Precision Rebuilders is most likely your best source.  If they do not have it in stock then they can also rebuild yours.
They refer to the Midland Ross unit as a Hypower unit in their catalog (page 1-38; pdf page 40)

Dave

[Vanessa]

Great! Thank you so much, I really appreciate it.