Sorting out an air conditioning fan that has rusted up
A chance inspection of the fans mounted on the air conditioning condenser resulted in Gavin Brown at the MG Car Centre in Launceston, Tasmania finding rust and a way of cleaning it up. This note will be useful for members with the Japanese specification A/C system and it includes a couple of tips to help reduce future rusting difficulties. (Feb 03)

Recently we had a front bumper off an RV8 and we were just generally looking over the front of the car as it sat on the hoist. I spun one of the air conditioning fans mounted on the air conditioning condenser and it had a very crusty spin to it. Upon inspecting the fan two problems became apparent:

Grit on the top of the condenser which was hitting the fan blades.

Body of the fan was rusting and the flakes were falling inside the fan blade, causing tight spots in the fans rotation.

They had to be fixed otherwise both problems could see the fan prematurely burn out.

Upon initial inspection I thought that you might not be able to remove the fans without letting the gas go in the system, but luckily this was not the case. To remove the fan you need to remove the outside condenser support brackets and loosen off the inside ones too, then you can then gently push down the condenser to expose the top inside fan bracket bolt which requires an 8mm open ended spanner on the bolt head and a 10 mm ring spanner on the nut underneath the core. After all four bolts are removed at each corner of the condenser, the fan then can be slid forward still fixed to the metal base bracket. You then need to remove the 4 Phillips head bolts which finally allows you to separate the fan from the metal base bracket.

Looking at the fan more closely showed that the fan body rusts on its lower half because of a design fault Rover did not think about when deciding to use these generic fans. The fan blade wraps itself around the body of the fan and leaves about an 8-10mm gap at the top which means that whenever the fan gets wet, the water drops inside the fan blade and, because there aren't any drain holes, it acts as a bowl to submerge the lower half of the body. This rusts it out, dropping the rust flakes on the inside of the blade and thus potentially burning out the motor.

The next job was to remove the blade from the fan, turning the fan over exposes a circlip which holds the fan blade on the shaft. Using a very small straight screw driver, the circlip can be slid back carefully, watching it in case it flies off somewhere. The fan blade is a tight press fit on the shaft so a bit of wiggling saw it slide off the shaft reasonably easily.

This exposes the base of the metal body where one half of it is as new and the other half, the lower half that points down, is very rusty. The body can now be removed from the plastic shroud by peeling off the rubber seal that covers the top of the motor to expose 4 Phillips self tapping screws. Upon undoing these screws the fan body slides out backwards from the plastic shroud. To fix the rusting body, we ran it over the wire wheel to remove the surface rust and then with the wire brush to get in to the places the wheel could not reach. However one point of warning, if you use the wire wheel, do be careful not to touch the electrical wires as it will break them off. We then used a rust converter to neutralise the rust after which we painted the fan body with silver paint. One of the bodies we did had rusted through in a couple of small pin holes which we feared welding up so it was decided to use a sealant to fill the hole.

Installation was the reverse of the above procedure, however to stop the fan blade from filling up from water and rusting again you could drill small holes in the lowest point around the fan. But you will need drill the holes so the fan doesn't become unbalanced. My recommendation is that after washing your RV8 or driving it in the rain you should turn the air conditioning fans on for about 20 seconds to spin the water out of the inside of the fan blade. I have heard of one other car which must have sat for a long time without the air conditioning turned on, as the body of the fan had rusted out totally and upon removal, the fan the blade was found to be just sitting on the air conditioning condenser! This procedure is a must as every car will eventually do the same.

MG Car Centre
Gavin Brown (Blaze 1656 and Woodcote Green 0693) and runs the MG Car Centre in Tasmania and import RV8s to Australia. All cars are "ADR complied" and can be delivered anywhere in Australia. The "ADR compliance" means the RV8s have a compliance licence confirming modifications have been carried out so the vehicle conforms with the Australia Design Rules. These measures are to regulate the market and protect the Australia car market from "grey" imports. The MG Car Centre provides a full servicing and spare parts service for RV8s and MGBV8s. They have supplied a number of RV8s to customers downunder and can provide customer testimonials if requested.

The MG Car Centre
2-10 Herbert Street
Australia 7250
Tel: +61 (03) 6334 4366

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