Second electric vacuum pump

[DamoPeru]

Hi guys,
I am about to install an exhaust brake on my HZJ78, it requires tapping into a vacuum line for operation. Whilst it shouldn't have a huge effect on the vacuum, as we all know the brakes are rubbish at the best of times, and one brake booster kit I saw for a double diaphragm booster also included an electrical vacuum pump to boost the existing system, it seems the bigger booster requires more vacuum. So I thought if I'm robbing even a bit to operate the exhaust brake, better to replenish it and a bit more constant vacuum replenishment might even be better for some situations. Anyway, I got a 12v pump without really researching the details but now I'm wondering where is the best place to put it to achieve the boost I'm looking for, or maybe I'll even use the new pump to setup an isolated system for the exhaust brake and leave the factory system as is. What do you reckon? Cheers, damien

 

[Hulsty]

For extra vacuum I used a tank into the existing system as the brake booster takes a fixed volume each time the pedal is depressed.

If you are intent on using the 12V vacuum pump, I would set up a vacuum tank that both the standard and 12V pump draw from, using check valves in each, so if one fails you go the other and there is no reversion. Then run lines from your tank to the thing that needs vacuum.

The standard 1HZ vacuum pump is resonable size and should not have an issue keeping up.

 

[DamoPeru]

thanks hustly, i like your idea of both pumps and components all directly to the tank. i'll go with that i reckon...

so how much of a difference did the tank make? had you already done the double diaphragm booster conversion or still on the standard? what size tank?

cheers,
Damien