Author Topic: Rebuilding the TC mechanical fuel pump  (Read 4087 times)

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Offline LotusJoe

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Rebuilding the TC mechanical fuel pump
« on: Thursday,October 26, 2023, 03:25:13 PM »
Joe Irwin
3927R TC Special
(The Classic Barn Find)


Offline EuropaTC

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Re: Rebuilding the TC mechanical fuel pump
« Reply #1 on: Thursday,October 26, 2023, 10:42:09 PM »
Ahhh, that's a blast from the past and no mistake. I remember doing the one on the Elan way back in the 80s, fiddling about with those flap valves and being so pleased when it actually worked afterwards !

Brian

Offline Bainford

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Re: Rebuilding the TC mechanical fuel pump
« Reply #2 on: Monday,October 30, 2023, 09:50:17 AM »
I did mine a few years ago. Dealing with the staking that retains the valves was a bit tricky. Not difficult, but without instruction, I was unsure about grinding away the old staking with a Dremel, and establishing new stakes during assembly. Like Brian, I was pleased it actually worked when I put it all back together.
The Twin Cam plays the symphony whilst my right foot conducts the orchestra. At 3800 rpm the Mad Pipe Organ joins in.

Trevor

Offline 4129R

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Re: Rebuilding the TC mechanical fuel pump
« Reply #3 on: Monday,October 30, 2023, 10:03:31 AM »
I have just had fuel pump failure, so I am about to recondition the 3 spare pumps I have.

Presumably you carefully grind away the depressions holding the valves in place, remove the disc valves, and then dent the ally rim to hold them in.

I also presume the valves are one way and you have to fit them the right way around.

Any tips?

Offline 4129R

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Re: Rebuilding the TC mechanical fuel pump
« Reply #4 on: Tuesday,October 31, 2023, 04:47:36 AM »
I have just had fuel pump failure, so I am about to recondition the 3 spare pumps I have.

Presumably you carefully grind away the depressions holding the valves in place, remove the disc valves, and then dent the ally rim to hold them in.

I also presume the valves are one way and you have to fit them the right way around.

Any tips?

I gave up removing the "staking". I was afraid I would damage the aluminium casing around the valve.

I have just ordered a new glass bowl pump from SJ Sportscars for about £100.

Offline EuropaTC

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Re: Rebuilding the TC mechanical fuel pump
« Reply #5 on: Tuesday,October 31, 2023, 05:10:58 AM »
Out of interest, what was the failure due to ?
The one thing that's bugging me with E10 petrol is the rubber components we have in our cars so I wondered if you'd had the flap valves deteriorating ?

Brian
 ps - well, if you've got a new one on the way you might as well crack on with at least one of your old pumps. It's such a long time ago I can't remember doing it but given how I was back then I would imagine I just cut away the old staking and levered the valve out. Then I'd most likely just picked a different spot to hit with the screwdriver and stake the new ones in !

Offline Bainford

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Re: Rebuilding the TC mechanical fuel pump
« Reply #6 on: Tuesday,October 31, 2023, 08:50:37 AM »

 ps - well, if you've got a new one on the way you might as well crack on with at least one of your old pumps. It's such a long time ago I can't remember doing it but given how I was back then I would imagine I just cut away the old staking and levered the valve out. Then I'd most likely just picked a different spot to hit with the screwdriver and stake the new ones in !
That's what I did. I carefully removed as little material as possible to remove the valve. Thinking back now, I may have actually mutilated one of the valves and pried it out with a screwdriver after removing some of the stake material, making it easier to remove the remaining old stakes with a Dremel while keeping the bore clean and free of gouges. With the new valve in place, I carefully staked it in place with a small chisel-like tool. It doesn't take much. One valve was more difficult than the other, and it's been a while so I forget which one. I took some photos at the time; when I get home I'll try to remember to post them to this thread.

For what it's worth, the failure that caused me to rebuild my pump was my sump filling up with petrol over the winter hibernation.
« Last Edit: Tuesday,October 31, 2023, 08:57:09 AM by Bainford »
The Twin Cam plays the symphony whilst my right foot conducts the orchestra. At 3800 rpm the Mad Pipe Organ joins in.

Trevor

Offline Bainford

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Re: Rebuilding the TC mechanical fuel pump
« Reply #7 on: Tuesday,October 31, 2023, 08:53:12 AM »
.

I also presume the valves are one way and you have to fit them the right way around.

Any tips?
Correct. One faces up and one faces down. Note which is which when you disassemble the pump.
The Twin Cam plays the symphony whilst my right foot conducts the orchestra. At 3800 rpm the Mad Pipe Organ joins in.

Trevor

Offline 4129R

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Re: Rebuilding the TC mechanical fuel pump
« Reply #8 on: Tuesday,October 31, 2023, 09:52:41 AM »
Out of interest, what was the failure due to ?
The one thing that's bugging me with E10 petrol is the rubber components we have in our cars so I wondered if you'd had the flap valves deteriorating ?

Brian
 ps - well, if you've got a new one on the way you might as well crack on with at least one of your old pumps. It's such a long time ago I can't remember doing it but given how I was back then I would imagine I just cut away the old staking and levered the valve out. Then I'd most likely just picked a different spot to hit with the screwdriver and stake the new ones in !

Firstly I would like to nominate myself as "plonker of the week".

The old fuel pump was covered in oil so I thought the gasket was leaking. I took out the pump, cleaned it up, fitted a new rubber diaphragm, didn't bother with the tricky valves, refitted the pump, and it did not work. I overhauled two other pumps with new diaphragms, tried both of them, and none from the 3 worked. I thought the valves must have broken.

It turns out that I was fitting the pump top to the pump bottom 180' out, and all three pumps were pumping backwards. Idiot.

But .................... a success. I used a Stanley knife, went around the circumference of the valves to clean up the staking, then used a 10mm wide metal chisel, punched it through the centre of the valves, wiggled the valve north and south, punched through the valve east and west and wiggled the valve, and I removed two pairs of valves very easily. I used a long socket to drift the new ones back in place.

Tomorrow I change the pump 180' and it should all be fine again. Fingers crossed.

Offline EuropaTC

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Re: Rebuilding the TC mechanical fuel pump
« Reply #9 on: Tuesday,October 31, 2023, 10:10:17 AM »
Firstly I would like to nominate myself as "plonker of the week".
That's a hotly contested award.....     I'm pretty sure I can do something much dafter than that !

For example...   

I've just bought a 4 post lift which has arrived without any instructions so I'm currently wandering around the internet looking at Youtube videos and for clues about how I can wire it up without generating clouds of smoke from the wiring.....

 :)