1982 3B - Vacuum Pump Issue

[Snow Peak]

Hey guys, I've got an issue with my vacuum pump.

I'm getting a loud squealing/whiny noise coming from it. The alternator was just rebuilt so didn't think it would be that. On Tuesday I went down to the shop and got a used vacuum pump swapped in. At first the noise was gone but after about 10 minutes of driving I could hear the noise again.

On Wednesday morning I went back there and swapped in a used but confirmed working alternator to see if the issue was indeed that; still didn't fix it.

I went out of town after swapping the different alternator and took it to a shop here in Kamloops, BC. First we tried swapping the check valve; no difference. We then pulled the vacuum line off and voila, the issue went away. As soon as you plug it (with your finger) or put the vacuum line back on, the noise comes back.

I made a video of the noise; hoping you guys may have solutions. Both shops I went to have never heard a vacuum pump make this kind of noise.

 

[roscoFJ73]

What parts did they replace on the alternator rebuild? If they only done the electrical side, it may have a bad bearing .When you take the load off the pump ,you take the load off the bearing also.
I think we had one like this before on the diesel forum.

 

[Snow Peak]

Hmm, I think they only did the electrical side so that sounds like a good reason it's making that noise. The second alternator that I swapped in also made the same noise...two alternators, both with bad bearings :O

 

[roscoFJ73]

I cant remember if they have bearings or bushes. Yeah 2 bad alts is a bit much of a coincidence to swallow. But vacuum pumps are tempermental things and you could have 2 bad vac pumps.
Its no wonder Toyota did away with the alternator driven vac pumps on newer generations of engine.

 

[lostmarbles]

Is the vacuum pump getting it's lube oil from the engine properly?

If it's running dry it will certainly be noisy like that (assuming you have an OEM vacuum pump there).



PS. My alternator has a ball-bearing at the pulley end and a bush at the rear (with the rear bush being lubricated with the vacuum pump oil)...