Triumph Repair: 79 TR7 Water pump, impeller blades, slide hammer

Question
Any tips on how to remove the 12 vane water pump on a 79 TR7?

Answer
Hi Michael,

Be sure to drain the cooling system and the block too or coolant will run down into the crankcase when you pull the pump.

As you probably already know the pump is in the top of the block. Be careful when getting a new pump as I seen some aftermarket pumps that were wrong for the application. Two factors are involved. the impeller (no matter how many blades) must have the correct angle and match the angle of the top cover. A second factor is the angle of the teeth on the pump drive gear. I have run into aftermarket pumps that had the correct impeller but the wrong gear angle. So be sure the now pump matches the old pump gear and angle of the blades and that they match the top cover. As far as i know there were only two different gears and two different impeller angles. But I have seen several different designs in impeller blades and number of blades. I think there were only two of each from BLM.

Different thickness top cover gaskets are available to set the clearance between the head of the bolt of the impeller and the top cover. (.010" to .025") I like to check the impeller clearance too with modeling clay.

Keep in mind that the bolt in the top of the impeller is left hand thread. If you don't have the special tool to thread into the hole and slide hammer the pump out you can fabricate an adapter to use the bolt on a slide hammer. I made one with a foot and half piece of threaded 1/2 in steel pipe. I cut a short piece of steel pipe that would slide over the 1/2 in pipe and put a threaded cap on both ends with a hole in the bottom one. I then used the bolt out of the pump to bolt the cap on to the top of the impeller and then screwed my 1/2 in pipe into the cap and used the larger pipe as a slid to hammer it up out of the block. You may have to clean the inside of the cap that you will put the bolt in because of the length of the bolt. I used a die grinder to clean up the inside of the cap and then ground the outside down a little so the I had a lot of threads in the pump shaft.

Do a supper cleaning job in the block before putting the new pump in. Some impellers had two holes to gain access to the lip of the brass sleeve to drive it all the way into the block. Never beat on the impeller bolt to drive a pump into the block. On many of the pumps there were no holes, so on these don't put the impeller on the shaft until you have the shaft and the  brass sleeve seated all the way home. Then install the impeller and do the clearance checks.

The TR-7 had several odd designs that really tripped up regular mechanics. Let me know if the car has over heated as there are several things that need to be attended to.

Howard