Speedtoys

I found a leak...at the low side R134a fitting.

I need to replace something here..duh..but does the R134 adaptor over the OEM R12 valve has its own seal, or is it really the schrader valve in the R12 fitting below that, that needs replaced.

I spose I'll do both of course. just in case...just thought I would ask.

dprantl

It depends on what type of R134a fitting it is. There are those that have a plunger that can depress the existing R12 valve core, and there are ones with their own valve core and the old R12 valve core must be removed.

Dan
'91 928GT S/C 475hp/460lb.ft

Tom. M

I've seen both types of adapters..some are just a screw on adapter that extends the reach of the old schrader valve...and others require you to remove the schrader valve inner part and then the new adapter is screwed on (with sealant around the threads)..this adapter will have its own new valve.

I had a bad high side schrader valve and had to evacuate the whole system, change out the valve (did both)..and of course the low side broke and took an extra 1/2 hour to remove and replace..

Speedtoys

Ill see what HF has in stock tonight for that.

SeanR

Go to NAPA and get a quality one. I've dealt enough with the cheap ones that if one comes in with them, the owner has two choices.

Take it back to the shop that put them on, or let me change them to some decent ones.

Bill Ball

HF will not have it individually. NAPA or any other car parts store will have it.

dr bob

The AC schraeders have different seals vs tire valves, and amazingly the current ones have green HNBR seals. The adapters tend to be one-time-use pieces, with a squish-once seal where the adapter sits on the tapered end of the R-12 fitting. I like the ones that have their own Schraeder valves, but you MUST take the old Schraeders out for them to work. I've seen the original valves damaged when the adapter is installed, with the pin rolled into the flare end. Kinda spoils the seal there.

Buy good adapters, stay away from the bargain bits at the chain POLAPS places. You'll be happier.

Speedtoys

Then...why do the 134 adaptors, have a pin on the INSIDE of them..if not to press down on the R12 valve?

dr bob

It's there for folks who don't know to take the old valves out first I guess. You'll need to put new correct schraeders if if you keep them at all, plus what's in the new adapter.

Speedtoys

Done that a few hrs ago.

Will see what Vacuum says on the gauge in the AM.

dr bob

Jeff--

I've been trying to leave a pump on service cars overnight, after an initial gross-leak vacuum-depletion check. Seems like more moisture and air can be boiled out if left on longer. The extra cost of the power for the 3/4 HP vacuum pump motor overnight is not so much. With gas ballast closed, it's a little noisier but what the heck, it's out in the garage... Cheap insurance.

Speedtoys

Not worried about overheat of the pump? They get -hot-...

Rob Edwards

Done 2 overnights with my Robinair 15600. It does get very warm, but it was at 650 microns in the AM. About as good as I think that pump will do.

Jim Devine

This is a good read about the vacuum pump.
They mention changing the pump oil frequently- see page 5. It's
available at any hvac supply. Makes sense.
I have the same Robinair 15600 & I think it's
the pump that is in the Robinair evac/ charge stations, so you should get the same results as
if you took it to a shop. Probably better, they usually don't maintain their equip like this.

http://www.airclean.us/uploads/Robinair.pdf

This is a good read too:

http://www.robinair.com/acsolutions/...m/acvacuum.php

Speedtoys

Mine ran for at least an hour yesterday late evening (cold outside)..and went out here 12hrs later, to find just _barely_...noticeable rise on the gauge. I half expected that due to being a LOT warmer out now, sun on the hardware under the hood, and a few specs of moisture finally boiling out. Letting it run another 30min now.

FWIW...also got a 30lb can of 134 for $75 last night. That was nice.