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Low pressure charge port leaking

7K views 13 replies 7 participants last post by  HeavyT56 
#1 ·
I recharged the system last summer and now it's in need of another charge. When I unscrewed the dust cap, I noticed a leak in the nipple. It's the plunging portion of the valve and not the canister itself. I tried fiddling with it to make it seal, but that didn't accomplish anything.

Is this leak due to low pressure in the system (unlikely)? Or is this just a bad port valve that needs to be replaced? Or would the entire canister need to be replaced? What would that take and what would be the cost? I imagine the entire system would need to be evacuated first. Thanks
 
#2 ·
Your right. I would just replace the whole canister, its fairly cheap, like 30 bucks. The new one come with a new valve. Just be sure nothing else is leaking(lines, compressor, high side valve)otherwise u will be evacuating and recharging again.
 
#3 ·
Just looked at RockAuto and the canisters are <$20. I think this is a done deal. Now, in the Haynes manual, "fresh refrigerant oil" is mentioned as well as o-rings. Would a new canister typically come with those (they're not mentioned in the RA ads).

I may self evacuate the system accidentally unless a service shop is easier.
 
#4 ·
The delco one I bought off amazon came with some, but were wrong. Oil is a must when you replace a component in the system. You may want to get o rings from parts store for the lines and pressure switch.
 
#5 · (Edited)
If thats your only problem, just replace the schrader valve core. AC delco sells them for $5. Most of those under $30 dollar receiver drier canisters are made in china. Even AC delco is making them in china now. If you are fast, and can fight a good force of outgoing gas, You can even remove your leaker, Stab the new one in and not even too much refrigerant. Charge it back up with a can and you are fixed. Most places charge $80 to evac and recharge + half hr or more to change the canister + parts. If you decide to bring it to the shop, buy a new high side fitting too. They are known to leak (you know when you see oil in the cap) They screw into the high side line.

Receiver driers come with new o rings so you DONT need to buy them.
 
#6 ·
use a tire stem core tool and tighten the shrader valve first and see if that takes care of the leak.
 
#8 ·
The dust cap is not just to keep dirt out, it's an actual seal. I have a car with a leak on the high side schrader valve which leaks enough that you can hear it bubbling with the cap off. Snugged up the cap and the system still cools fine over a year later.
 
#9 ·
I'll probably just grab a quick can of R-134a and snug up the cap first. If it works, then I'll save the ~$200 of drain / recharge costs. If it doesn't work, I'll just be out $20. Worthwhile gamble.
 
#10 ·
Try to tighten the scrader core first. If that doesnt do it, replace just the core. If that doesnt do it, you will need to replace the canister. If you have the canister off, see how much oil is in it if any, and thats how much you need to add. Do not over add the oil and yes, you will have to use a vaccuum pump to vacuum the system if you replace the canister. So I would try to fix the core valve first.
 
#11 ·
back in the r12 days snap on tools sold a pricey gadget that could change out the core without losing the charge.
googling shows other companies now sell similar tools, one I looked at was in the low $30s.
 
#12 ·
Alright, I guess I'll try to replace the schrader valve first. On Rockauto, there are three choices:

FOUR SEASONS Part # 26775
$8.68
Caps and Valve Core Seal Kit; w/ Hi-Side Primary Seal

FOUR SEASONS Part # 26779
$11.34
Caps and Valve Core Seal Kit; w/ Hi-Flow Valve Cores

FOUR SEASONS Part # 26778
$25.79
Caps and Valve Core Seal Kit; w/ Areoquip Fittings

Anyone know the difference besides the price?
 
#13 · (Edited)
The shcrader valves I use are:

ACDelco 15-1119 Schrader Valve - for the low side




ACDelco 15-5438 valve - for the high side

Some parts list both part descriptions as heater control valves. F if I know why they did that. Ive used both parts w.o. any problems. Rock auto lists the parts under heating and AC- Schrader Valve. The Low side valve core is around $5-9 dollars on the net, yes its a rip off for a $.30 cent part. Who knows, a tire valve stem core is probably the same part, however the AC valve looked like it had more robust seals on it.



Replace the HS fitting when performing AC repair. Its cheap leak free insurance.


I don't now about the four seasons parts
 
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