Hydrovac Testing 

Thank You so much for this video! About to do my first R&R on one of these and needed to hear every word you had to say on the hydrovac. I will have a much better day now.

By far the Best video on hydro vac testing i have seen yet on RU-vid . Thanks so much for sharing this much needed do it yourself video .

This is an older video but by far the best on these older systems. Thank you for an informative video.

Very easy to understand. Thank you.

Nice video. That unit is installed on my 1954 Ford F-750 fire truck. I had the unit rebuilt when I restored the truck.

I am a Vietnam Era Vet. I have years of experience with these boosters. The vacuum lines have a tendency to rust through allowing humidity and moisture to get in around the diaphragm chamber resulting in booster failure and defaulting it to manual brakes. This also creates a vacuum leak effecting the performance of the gasoline engine (diesel engines do not have a vacuum from the engine to the booster). There is an atmosphere tube on the back side of the booster diaphragm that also gets humidity into the booster chamber and accumulates at the bottom eventually causing a rust hole.

Lifesaver

Good question for you. I have a 65 Chev C-60 and I cannot find a bleeder valve on the hydro vac anywhere! I can't get the air out of it... Was there another way to bleed them? Thanks!

I have been pulling my hair out trying to figure out this problem with multiple pumps to get brakes to work. My wife’s leg is wore out from pumping the pedal while I’m at the bleeders! 1959 Ford B600 school bus with Midland set up. Thanks for explaining what theses lines are for I’m starting to get it now. Can a guy put a 2000 psi hydraulic pressure gauge on the output of the slave cylinder? 960 psi for the 8 1/8” booster is what it should be give or take based on vacuum. That could tell me if I’m good or bad at least at that point.

1800 loadstar ih. Tandem hydra vac booster. Had booster rebuilt locally afew years ago. Problem is it takes 4 or 5 seconds for brakes to release after pedal is released. Have been told if brakes are not set up close enough this causes hydra vac to extend to far and take to long to release. Is this true. Thank you

I have a rebuild Midland hydrovac unit on a 1970 Dodge D400. I am about to install my 3rd master cylinder. This hydrovac system requires a 2nd "pump" of the pedal to get the brakes fully engaged. All this pedal travel wears out the MC, I assume

i just purchased a 1966 D500 Dodge with Holmes 500 wrecker on it. has been sitting since 2001. installed new master cylinder today also new lines. bled master cylinder then installed new line to the hydrovac. i have plenty of fluid going to hydrovac but still brake pedal goes to floor no brakes. guess the hydrovac unit is locked up. can you help me looked online and don't see them listed to buy. todays date is 10/2/2021 thanks for any help you can give i am located in southeast Alabama USA

where can i purchase a rebuild kit for my 62 international 190 series. it is a barrel style. I see Cardone sells the entire unit but i want to keep all OEM parts

I have a 1963 GMC 4000 and I need a new booster and slave cylinder. Where do I order this at?

Iwant anew Howmach it price

I need one of those for my 1965 Dodge travco motorcoach but I do not know which one to get. Any suggestions?

What if the engine stalls when you apply brakes

Wear can I buy this unit. I am unable to fine a new one like this any place

Wait so hydro acts don't come with check valve built in ?

hi, I have a '64 International 1600 4x4 very high mileage truck and a '69 International 1700 very low mileage truck (15k miles). Both have a single circuit master cylinder with a hydrovac. Both hydrovacs seem to work ok and seem to look identical to each other. I would like to convert to a dual circuit master cylinder in the IH 1700 truck and will need to use the hydrovac from the '64 so each circuit will have its own hydrovac. Some old IH Loadstar buses used this system. I'm thinking I want the amount of boost supplied by each hydrovac to be exactly the same and the only way to do that is if both hydrovacs have exactly the same current rebuilt parts inside of them. Several questions: -1- Would it be better if each hydrovac uses its own vacuum storage tank or should they both run off the same storage tank? -2- Is there a dual circuit master cylinder that will bolt directly in place of the single circuit master cylinder or will I need to fab a custom firewall mount? -3- Where can I purchase two complete rebuild kits and do the kits come complete with pistons etc like a master cylinder rebuild kit? -4- And are the kits compatible with DOT 5 brake fluid? The IH 1700 has always used DOT 5 brake fluid and the '64 IH 1600 has only used Dot 3 brake fluid, another reason why I will need to rebuild them. I know DOT 3 and 5 should not ever be mixed together. -5- And your recommendations on the layout of the brake lines, please. Should I have each circuit go to one axle or since each wheel backing plate has two wheel cylinders, should I have each circuit go to one wheel cylinder. That seems like the best way to do this, but that's a lot of brake lines. Thank you.

What causes a rock hard brake pedal?

Where can I get dual hydrvac 1980 Chev c70