Automotive Air Conditioning Information Forum

Hello jfklein!

At the same time you're dealing with your GTI slow leak, I also had a slow leak on my 2001 Dodge Caravan.
In my case it was a bad high side port. I was able to unscrew the old one and install a brand new one.
I also found that all the rubber O-rings at the evaporator were all smushed, disfigured and a bit hard, so I replaced them all.
I'm thinking they could have been original.

At this point she's holding vacuum for days without any vacuum loss.
Reference material says yours has replaceable schrader valves but not a screw in replaceable port like this Caravan has.
I haven't read the entire thread in a while and can't remember but I figure you replaced that valve.

If not, it's really easy to replace.

Diametric wrote: Tue Sep 08, 2026 6:18 pm Hello jfklein!

At the same time you're dealing with your GTI slow leak, I also had a slow leak on my 2001 Dodge Caravan.
In my case it was a bad high side port. I was able to unscrew the old one and install a brand new one.
I also found that all the rubber O-rings at the evaporator were all smushed, disfigured and a bit hard, so I replaced them all.
I'm thinking they could have been original.

At this point she's holding vacuum for days without any vacuum loss.
Reference material says yours has replaceable schrader valves but not a screw in replaceable port like this Caravan has.
I haven't read the entire thread in a while and can't remember but I figure you replaced that valve.

If not, it's really easy to replace.

You are correct on both counts - both Schrader valves were replaced by the last shop that tried to diagnose the leak and the port is not replaceable, it is one piece of aluminum brazed to the low side pipe.

Since this problem has been going on for over a decade and it takes two years to know if any solution actually works, I am leaning towards getting the FreezeCap devices and using Nylog Blue as well to seal up both ports. If that doesn't stop the leak at least I will know it isn't coming from the ports.

This is sounding more like a Freezecap sales pitch. I see very little benefit in them other than that they are a fancy service cap. If a good cap, O-ring, and Nylog won't seal it, an $80.00 service cap won't either, IMO. If people are crushing the O-ring on the service cap. That's the mechanics' problem, not a service cap design. Better add some Ice32 in that system as well. LOL

Tim wrote: Tue Sep 08, 2026 7:15 pm 43-MT2912

Why are there holes in the top of the caps in this kit?
From what I've seen, some caps have holes, some don't. I don't get it because I thought the caps are the primary pressure barrier for the ports.

Tim wrote: Wed Sep 09, 2026 12:58 pm This is sounding more like a Freezecap sales pitch. I see very little benefit in them other than that they are a fancy service cap. If a good cap, O-ring, and Nylog won't seal it, an $80.00 service cap won't either, IMO. If people are crushing the O-ring on the service cap. That's the mechanics' problem, not a service cap design. Better add some Ice32 in that system as well. LOL

I've taken a fairly close look at the design of the FreezeCap device (and the A/C QuickCaps too).

I think the FreezeCap device might be designed to seal over a damaged port rim because it uses a flat elastomer disk instead of an o-ring for sealing and it has a dial that is used to push the sealing disk onto the rim.

An o-ring requires less force to create the contact pressure needed to seal because it contacts the sealing surface along a thin ring. But if you think about it it requires a smooth sealing surface with few imperfections that can create a leak path under that thin ring.

On the other hand a flat elastomer disk requires a lot more force to create the contact pressure needed to seal because it contacts the sealing surface along a much wider ring. But I think it can handle more imperfections in the surface by sealing around one edge of the imperfection. So I think this explains why FreezeCap uses a flat disk and a dial to push the disk onto the rim. I think the elastomer disk will kind of wrap around the curve of the rim to a certain extent covering imperfections that might create a leak path under an o-ring.

This is why I am leaning towards the FreezeCap device, it's not a sales pitch. I'm actually undecided at this point.

I'm trying to confirm if the A/C QuickCaps device can be adjusted to push the o-ring that it uses for sealing into the rim, like the FreezeCap. If it does, this might be the superior device because their design has the o-ring sealing more around the edge of the rim, rather than right on the crest of the rim. I figure the edge of the rim is less susceptible to damage than the crest. At least on my car the damage is all on the crest of the rims.

They do not, unless you have a damaged cap. That "dimple" is from the injection tooling. Besides, we offer a similar product if you want to spend that much on a service cap. Still stand behind a new R134a cap/O-ring and Nylog. If you're cranking down a service cap to crush the cap. You're doing someone wrong. That's my opinion.

43-MT6094