Thread: Heat from transmission tunnel

Davo is spot on about flushing the system while you have the chance.

Make sure you check the TX valve. It's often overlooked. The TX valve can be the cause of compressor shutdowns (blockage) and poor cooling / pressure issues. the gauges on the ac manifold will tell you what pressures each side is running when it's charged anyway - all I'm saying is make sure you have checked everything because the system is designed to run sealed, so introducing any contaminants is detrimental - this is why a lot of fridgies will not work on an open system.

Hoses are just that - replaceable and not stupidly expensive. For the money, I would actually replace the hoses, You can even DIY with a hose crimper and buy your hose/fittings from ashdown etc. Why would you replace them rather than re-use? because the age and engine bay heat will see them off sooner than you'd maybe like, especially something that has aged.

receiver drier - it's something you replace regardless. They are a dessicant inside and absorb the moisture from the system, so if they are exposed to atmosphere, they're rooted.

Compressor - worst case probably rebuild it? but a couple of good flushes, and re-oil, making sure you get nothing but clean oil before you fit it up for the final time. Oh - and make sure your oil is compatible with the compressor AND the refrigerant. there are different oils out there.

I'm not a fan of hychill, it's extremely dry as a gas - but totally understand the r12/r134a arguments for an against. IMO R12 was and still is the best gas, but here the EPA say it's harmful to the atmosphere.... in reality it's far less harmful than other gasses, but you can't argue with government bigots.

My system took 1.3kg of r134a, and is ice ice baby too cold.

Make sure your wiring of the pressure switches and compressor clutch are sound.

One thing I really love about the RRC is the size of the evaporator. It's truly oversize, and because of this, the system performance is awesome. If you compared it to the ****weak evap core in say, my 560SL merc, then you'd die laughing.

But getting back to the original 'heat soak' issue.... in my 91, the floor and tunnel insulation are quite thick, and do a fairly decent job. I'm not sure how earlier models were done, but one thing to definitely consider is using something like dynamat etc underneath the factory insulation, or replace it with something more efficient.

I have a fair bit of dynamat experience, and will say it serves 2 purposes. The main purpose is sound deadening. Secondary purpose is heat shielding. It was not designed as a heat shield as the primary consideration - that's a byproduct of installation. It's specifically designed to add mass to a panel to stop resonance.

So if you are looking for a pure heat shield, then you'd need to look towards Shane's example of a foil backed closed cell foam type of insulation material.