Om617 swap vac pump possibility
 

Hi i recently found an ooold toyota in the junkyard the other day, and was very surprised to find an old diesel under the hood. I was even more surprised when my friend pointed out that the vaccum pump was driven off the back of the alternator. Anyways, ive read about problems associated with the vaccum pumps failing and dumping bearings in the motor, for those of us using om617s in toyota or other chassis i wonder if this might be a good option? Im still running stock vac pump on mine, hopefully itll be fine for a long time but i thought this might be interesting and wondered if anybody had messed with this.

I'd be curious to see it. I don't think I'd swap out my 22SI alternator for one, but would like the option.



I'm running a VW/Audi electric vacuum pump, and just gutted the inside of my mechanical pump.

There were the norm on anything Japanese diesel for the 90s or earlier. They seemed to have fallen out of favour after about then.

You need an oil supply and drain for them. I've considered the swap myself, but you are limited if you want higher amp outputs. I've never had to "maintain" one so don't know how long they last but being oil lubricated vanes they probably last quite a while (just ask pilots about dry vacuum pumps vs wet ones)

https://www.ebay.com/itm/80-Amp-Alternator-for-Nissan-Patrol-GQ-4-2L-Diesel-TD42-01-

(Pics are of a SD33T and Toyota H engine i have here)

Good luck finding parts for those alternators.

if you only need vacuum for brakes, just go electric, and gut the mechanical pump or get a vp cover.

for electric, you need the pump, vacuum switch and relay.

Yes, electric is the way to go IMHO

The VW/Audi pump is NOISY, and you better have a stout relay running it. I welded the contacts on several 30a relays before upgrading. Heck of a startup surge.

The pump I'm using is pretty tame. its a clone of the ford booster pump. its really all you need.

I'll look into that pump when it's time to replace mine, or when/if it ever gets high enough on the upgrade list.

ACDelco 20804130 is a great one as well. Common on Chevy 1500 models.

So still no electric solution for auto transmissions?

Looks very nearly the same as the VW/Audi pump.

Interesting. It seems an elec vac pump and a new alternator may be in my future. I probably wont go back for the toyota alternator

1979 and older n/a automatic diesels don't use a vacuum modulator.

They only have mechanical linkage so no problems with constant vacuum leaking

I've had one of those alternators w/ rear vac pump bookmarked on ebay for years. About $70 for a rebuilt, but not sure there is clearance behind to the engine mount & damper. Interesting that they require an oil supply, since hadn't read that.

I also have a used Audi/VW electric vacuum pump (for their brake boosters), but haven't found an inexpensive vacuum switch (anybody?). Also, seems the jury is out on how long they might last running against the constant vacuum leak of the VCV in my automatic cars.