AC condenser and Radiator

[mprokop87]

Has anyone replaced the radiator and/or their AC condenser? The condenser on my unit is shot, it cracked open and is no longer usable. Dash AC isnt a big deal for me because we get a nice breeze in our unit even on the hottest of driving days.

My major concern is my radiator. On a 3 hour trip last year I could smell coolant and actually see it dripping down the radiator form the top. I am not sure of where the leak is without taking it out. I am going to be taking it out in the next few weeks and I would like to repair it or possibly replace it. Has anyone found a good quality source for a new radiator?

[ViewRVs]

I am assuming that you have the Chevy 454 in your 24'. (A 350 engine was actually an option for the 24' units.) I had my radiator re-cored last year. The shop could not find a replacement. It should be a quad-core radiator.

There are two ways to replace the radiator.
(1) Disassemble the front end or
(2) drop it out the bottom which requires lifting the front of the coach up. There is actually a thread here with pictures of this being done.

[martin300662]

Although the radiator on our 20ft (350) is not leaking.....it's out so we are getting it re-cored at a local radiator shop, just to be sure.

If you can get the radiator out (and we have the entire front end open at the moment so it is relatively straight forward) then any good radiator shop should be able to repair/re-core.

[mprokop87]

Thanks guys! I do have the 454 and it runs great! I am planning on dropping the radiator out in a few weeks, by the sounds of it I will just get it repaired. I have access to a lift so it makes things super easy. It was a breeze doing exhaust work last year [not me in the pic]...

[GTOChucky]

I agree with the others. Take the radiator to a radiator shop and they should be able to fix it for you. With respect to the AC and the condenser. When I bought my 1988 AS 325, the previous owner told me the dash AC didn't do much. The main reason it would NEVER do much is because the previous owner did not have a curtain to draw across the cockpit area. This curtain is a MUST. No dashboard RV AC system will cool the entire coach and with no curtain, that's exactly what the AC system will be trying to cool! With the engine right there producing more heat, the AC system has no chance of cooling the cockpit! Since R-12 is to expensive, I replaced the old compressor, flushed out the entire system with an AC solvent, replaced the expansion valve and recharged the system with a substitute refrigerant, Enviro-Safe. The only tricky part is figuring out how much oil to include with the refrigerant. I installed a full width cockpit curtain and the AC cools great, even on very hot days. Sometimes, I have to turn it down because the cockpit got to cold! You'll also need to determine the amount of refrigerant to use based on the original R-12 charge.

[mprokop87]

GTOChucky,
I already did a converstion to R134 refrigerant. I typically have my unit plugged in prior to a trip (almost all the time actually) so I can turn the rooftop unit on the day before we leave. That usually cools the cabin for a while once I unplug it. The R134 did a nice job cooling the RV but would only last in the system for a short period of time, basically enough time to finish testing. I recharged it with some dye and sealant in hopes that it would plug up leaks in other spots, if any, but it didnt last. I pulled a vacuum on the system and everything else seems to be holding fine. If I would have been a little more careful when replacing the engine oil cooler then I would not be in this situation. Oh well, lesson learned!

I have a condenser out of a late 70s caprice that I will try to use if I cannot find a replacement. Its the same size but the fittings and tubing is different. Even though I would love dash AC it is one of my lesser worries.

-Matt

[GTOChucky]

Matt,

If you can't find the leak in your dash AC system. Try this, find a shop that will pressurize your system with nitrogen, to about 30 lbs. With the size of leak you're talking about, you might be able to hear the hiss where the leak is. Vacuum pumps don't always show a leak because the system RUNS under pressure, not with a vacuum. The nitrogen pressure is equal to about what the low side runs at. The nitrogen will not hurt the system and of course will be vacuumed out before recharging with refrigerant.

I had a client who was in the building AC business. He showed me the nitrogen technique. I've haven't found an "auto shop" that had nitrogen around to pressurize an auto ac system.

If you get the ac working without any leaks, don't forget the curtain. Even if your dash ac is working perfectly, it will NOT cool your entire coach. Get your windows tinted also. This will help the dash ac and rooftop ac to keep your coach cool.

[GTOChucky]

Matt,

One more tip. Determining if your system has enough refrigerant oil in it. A completely new system is easy, check the documentation for the amount. The problem is in a system when only parts of the system are replaced with new components. Years ago, I found a package of small plastic cylinders that you push onto the low side ac valve. The escaping gas goes through the small plastic cylinder. Inside the cylinder is a packing that changes color in accordance with the condition and amount of refrigerant oil circulating with the refrigerant. I don't remember where I bought mine. But, there's a company in Canada that sells the cylinders. Here's the link Refrigerant Oil Tester | emzone