How much vacuum...

[JeepSJ]

...will a vacuum pump produce?

Now that I finally have the engine installed, I'm finding that some other pieces don't fit. I had intended to use a Hydroboost brake setup, but the accumulator won't clear my injector lines. I can't move the engine or the hydroboost mounts far enough for it to clear.

So, I'm looking at a dual diaphragm 8" booster and a vacuum reservior (like you would use on a car with a big cam). The question is - how much vacuum can I get out of a vacuum pump? I need at least 18" for the booster to work. My other option is to run an electric pump. I already own the vacuum pump for the engine, so I would prefer to use that.

[JeepSJ]

Anyone?

[charliepeterson]

The vacuum pump is good for at least 20".

[Kennedy]

I see 25" from a healthy pump on my Snap-On gauge.

Be sure to plumb it large and include the elbow/check valve at the booster.

[JeepSJ]

Thanks guys.

[FJ40 Cruiser Guy]

I just noticed your question regarding brake vacuum. There is an excellent tech site at... I believe it may be at IH8MUD. It is predominantly a Toyota Landcruiser enthusiest web-site but I recall an article involving the use of a small fire extinguisher cannister as a vacuum storage unit. The individual who submitted the info was in the process of replacing a vacuum cannister on a FJ60 (wagon). The article may be of some assistance?

I am in the process of installing a 6.5 L into my 1980 FJ40 LandCruiser. I am going to run an Advanced Adapters "Ranger Torque Splitter" between the bell housing and the stock 4 Speed tranny. I had initially purchased a hydro-boost system for the brakes but I believe now I will utilize a pully driven vacuum pump with a vacuum storage unit (a small fire extinguisher). Anyways, have a good evening.

[CareyWeber]

Originally posted by JeepSJ:
...will a vacuum pump produce?

Now that I finally have the engine installed, I'm finding that some other pieces don't fit. I had intended to use a Hydroboost brake setup, but the accumulator won't clear my injector lines. I can't move the engine or the hydroboost mounts far enough for it to clear.

So, I'm looking at a dual diaphragm 8" booster and a vacuum reservior (like you would use on a car with a big cam). The question is - how much vacuum can I get out of a vacuum pump? I need at least 18" for the booster to work. My other option is to run an electric pump. I already own the vacuum pump for the engine, so I would prefer to use that. JeepSJ,

Spend some time looking in wrecking yards becuase there are some hydro boosts that have the accumulator internal rather than exteranlly like the 6.5 truck units are. IIRC the 5.7 diesel uses the internal accumulator.

Search before asking a pirate4x4!! ;)
Try searching a www.pirate4x4.com/forum/ (http://www.pirate4x4.com/forum/)
http://www.pirate4x4.com/forum/search.php?searchid=176910

Here is a site with a thin one.
http://www.monsterslayer.com/jeep/HydroBoost.htm

The other way would be to mount it so the accumulator is on the other side yes upside down the master cylinder will still bolt on correctly.

Carey

[JeepSJ]

Upside-down is an interesting option. Looks like everything will fit if I do that. I may have some issues with the fluid lines, but those can be bent. This may be the option that I use. After measuring, it does not look like the 8" booster will fit - I would have to run a 7" and that wouldn't give me as much boost as my stock unit. If I can figure out how to make the hydro unit work, I will be a happy guy.

The biggest PITA is taking off the big nut that holds the booster to the mounting plate. The parts guy at my local GM dealer could not find a part number for that nut. Anyone happen to have a spare laying around?