Vacuum Brake Booster

Has anyone installed one of these in a CJ? https://www.amazon.com/gp/product/B07L96828D/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

I bought one for Wilbur my '55 wagon, but was thinking I might get one for Willie. But then I crawled under with it and don’t see any place to install under neath. So looks to me like either engine compartment or under dash. Thoughts?

 

My dad has one on his V6 flatfender mounted under the hood on the right fenderwell. It took some extra plumbing, but it's been working well for 40 years.

 

I hadn't seen these before, so did some quick research. They seem to be an inline booster for a single circuit. So for the front brakes, you would run a single front brake line from the master cylinder, to the remote booster, then split the brakes somewhere between the remote booster and the individual front wheels. Looks pretty straight forward. I'd first make sure you have a dual circuit master cylinder setup on the frame rail, then plan on running all new front brake lines and plumb the remote booster somewhere you can get to it and avoid anything that would cause vacuum leaks, like the exhaust.

There's some good info on them from the MG guys.

Remote Brake Servo


These instructions show them being used on a single circuit system to feed both front and rear brakes, but I wouldn't want to add another potential failure point on a single circuit brake system.

https://mossmotors.com/media/instructions/981-173.pdf

Here's another model.
Master Power Brakes

Mike

 

I installed one in mine years ago. Works but with the 9” brakes and big tires there only so much friction surface. I upgraded front brakes to 11” drums last year and made a substantial improvement. One issue with this booster is it only works with single circuit system, or put two boosters.

 

These have been around since the 1950's and as mentioned work on single circuit systems.GM had one they called "hydra-vac unit" I had that version on my '47 flattie.Worked great. I see used ones at swap meets.

 

Yep, I'd think their main problem is that they are a single circuit. I expect there's no reason you could not make the slave MC a dual system, and with some engineering I think you could design an all-dual system. Other than the MC going soft, there are plenty of failures of the wheel circuits a dual slave system would save you from. BTDT- the rear cross-axle tube on my J10 burst in the Home Depot parking lot. Brakes still worked sort-of.

 

I would love to have one of those for a dual MC system.

 

Hi, I put that booster on my brothers '62 Willys(bought it for him for his birthday), Bought it from Kaiserwillys, but they're available from other venders. It goes for about 399, but I got 20% cause a asked Boy, I got screwed if Amazons price is only 100bucks!

Overall, I'm not impressed, but that may not be fair as my brother has fairly large tires, with stock 9" brakes. I guess I was expecting it to feel it more.
It has to be used with the stock master single cylinder; I put a remote lid with the remote reservoir on his.



Thinking it wasn't getting enough vacuum, bought this auxillary vacuum pump (amazone) as its primary vacuum, may eventually incorporate engine vacuum plus this. It comes on after a few stops, runs for a few seconds. Not noticeable when driving, but when at a stop, it kind of vibrates ones feet a tiny bit.


Robs jeep with my corral for a glamour shot




On my current project, a '68, I went with Brennan Metcalfs disc brake conversionhttps://brennans-garage.com/products/trackick-disc-brake-conversion-bracket, I'm a way from getting to try it out, but I think I'd go with a better setup before buying the power booster in question and expecting extra ordinary results.


I've long since had this installed and the brakes bled. The pedal is high and very firm I think it's going to be good

 

You can just run one booster for each circuit. There are some bundled back-to-back for nicer packging, but it's basically an independent servo for each brake circuit.

Pricey one here: Master Power Brakes

Cheaper from England, but not sure what the shipping costs: Medium Dual Circuit Remote Vacuum Brake Servo from Car Builder

 

Having had nearly useless boosted 9" brakes on my CJ-2, I think the brakes are a bigger problem than the booster.

 

Do these run on engine vacuum like a normal booster?

 

The system I bought came with an auxillary vacuum canister, it has like a 1/8 hose, and take a lot of plumbing to get it in line. I didn't use it. On the F-134 freshly overhauled engine, I thought I'd be a smarty and connect vacuum to the line at the PCV valve as it wasn't connected, the pcv was connected but there was a fitting which may have gone to some thing else, but vacuum at that point was only 12-16, and at the base of the carburetor was the same, but the 90 degree fitting which leads to the pcv, closest to the "intake" was 22-26 which would have worked, and I'd still may connect that line in addition to the auxillary vacuum pump. The reserve on the item in question is relatively small and good for only a few quick stops, then power brakes start to fade and back to "normal" braking. A large reservoir would be greatly helpful.

 

Normal vacuum boosters have 11/32 or 3/8 hose running to them, i would presume this needs something like that.