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1981 Triumph TR8: Sorting the Cooling System

I hadn't originally intended on ripping apart the cooling system on the TR8. To be honest the car stayed wonderfully cool in the Arizona heat. It was one of those, "if it ain't broke, don't fix it" situations. But on my aborted long distance road trip the car decided that it had other ideas. The water pump started squealing something fierce, and I knew that it was only a matter of time until total failure, so it was time to replace it. Luckily, I had just acquired a parts stash from a fellow local Triumph enthusiast. He had owned a TR8 at one point and had squirreled a pile of bits away. He no longer has his TR8, but he still had those parts, so I took them off his hands. In that stash was a brand new water pump!

Since replacing the water pump requires draining the coolant, I figured I'd just go over the whole system while I was at it. Keep in mind that the car is already up in the air, properly supported with jackstands and the negative battery terminal is disconnected.

First step is to drain the coolant from the block. There's a drain cock on the lower part of the block. To keep things neat you can connect a length of rubber hose to the drain. Open it, then let the coolant drain into a coolant drain pan.

After giving the coolant time to drain it was time to start tearing out the old rubber coolant hoses. This is what I immediately saw after removing the coolant hose from the thermostat housing. What a mess! The amount of corrosion and literal eating of the metal is likely indicative of the rest of the system. It's obvious that this car was not maintained properly in terms of the cooling system.

The interior of the radiator hose is in similar straits. This is one of those aftermarket replacement hoses, not a stock molded one. The springs inside the hose have completely rusted.

Here's the thermostat and the thermostat housing removed and on the bench. The interior of the thermostat housing looks worse than a boat bottom covered in barnacles. The thermostat is still pretty clean (at least by comparison) and functions correctly.

Next we remove the lower radiator hose. There's still coolant in there (as you can see in the photo) so you need your coolant catch pan below as you dosconnect this line.

Disconnecting it from abovt is not as easy because the front area of the engine is pretty tight.

Here you can see that this radiator host is in similar shape: totally corroded out.

There's also piles of corrosion on and around the water pump.

I warned you that the area around the upper hose is tight. Well, it's not a good day out in the garage without a little blood. :)

We'll go ahead and remove the rest of the hoses now. The heater hoses, coolant overflow hoses and the like.

Minor blessing, the radiator connections look clean, that's a good thing and indicates that the radiator may not be in too bad a shape.

Undo the hold down clamp and remove the coolant overflow tank.

Here you can see the complete overflow tank bracket/clamp removed from the engine.

Now we'll get the water pump up on the bench to check it out. Note: when removing the pump there's not only different bolt lengths, but different bolt sizes. Keep careful track of the bolts as you remove them. The passages look relatively clear but there's a lot of corrosion all over the water pump.

Remove the water pump pulley from the unit by removing the three bolts. I find that my 18volt impact gun is perfect for these sorts of items.

Here you see the old and new units next to each other. Note that the old water pump doesn't have the proper British Leyland boss on it (right hand side of the pump base) while the new pump does. The pump I'm replacing isn't original to the vehicle.

After flipping the pumps over you can see the underside fo the water pump. The channels were suprisingly clear of debris. When wiggling the water pump shaft there definitely was some play in the unit.

Now mount the water pump pulley to the new water pump. I recommend red threadlocker on these bolts.

There's a lot of goop and gasket left on the engine matching surface. To ensure a good seal we have to clean ALL of this gack off. I use a mixture of cleaning solutions (orange cleaner or carb cleaner) and a razor blade.

Here almost all of the old gasket material, grease, oil, corrosion, dirt, etc. have been cleaned off the engine mating sturface.

I did have a gasket that came in the box with the new water pump. The gasket, however, had been damaged over the years and wasn't usable any more. Rather than cut a new gasket I opted to use Ultra Blue as gasket material.

My gasket gooping has never been elegant. This time is no different. Those who have done this before will note that I put a little too much on there.

Bolt the water pump back up to the engine block but do not torque it down all the way. Follow the cure time instructions on the ultra blue tube, and once appropriately cured, finish torquing down the bolts.

Much like the thermostat housing you'll see that the heater core tubing has been really badly eaten away as well. Since we're intending to dive into the heater area later (when we install the A/C) I've opted to bypass the heater core in the short term. I'll run heater hose the appropriate distance, but insert a system flush connector instead of connecting to the heater core.

Here's the collection of radiator and heater hoses removed from the vehicle. Because my TR8 doesn't have a stock engine configuration, this may differ from what comes out of your TR8

Here's the new sets of hoses all assembled and mocked up. When doing this sor of work always replace ALL the rubber hoses and ALL of the hose clamps. There's nothing worse than reusing a radiator hose clamp to have it break on the road!

Once you have all the hoses and clamps set, you can reinstall the hoses into the car. At this point your cooling system should be completely reassembled. Slowly fill the system with coolant. Turn the heater on full bore (if you reconnected the heater) and start the car. As the engine warms up the coolant will also, then at operating temperature the thermostat will open releasing any remaining air in the system. Top off the coolant at this point.

Finally, double check the coolant levels after a few days. Top it off if necessary.

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Contents copyright 2008, 2009 - Jody F. Kerr

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