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Rewinding a fuel reserve solenoid

Posted: Thu Nov 16, 2023 10:15 am
by David2021
Can anyone suggest a company that can/will rebuild the solenoid in the Lucas Reserve fuel unit?

Re: Rewinding a fuel reserve solenoid

Posted: Sat Nov 18, 2023 8:18 pm
by SHyslop
I've been hoping there would be a reply to this as I too could have done with one being repaired. Having failed to find a repairer, I did find a new old stock P5 unit which uses the same general arrangement but has a bend in the pipes but it should be possible to remodel it into the same configuration as for a P2.

However, what to do with a broken unit? The way I see it is that the operation is purely that of a solenoid which pulls on when the switch is moved to Reserve and springs off to Main. Being 12 volt, a similar idea in size is a point motor for a model railway but these are on/on and can be operated by passing contact switches so that power isn't required once the movement has been made whereas on the electric reserve solenoid, it appears to remain energised until turned back to main . However, I have seen this :

https://www.ebay.co.uk/itm/401403373678

but have not yet had a chance to compare its size to the original. I feel there must be potential to resuscitate these units with some proprietary item suitably modified to replace the solenoid and connect to the valve. It is, after all, a fairly simple electro mechanical unit but of the type which the iphone generation has left behind, hence the difficulty in finding repairers.

Re: Rewinding a fuel reserve solenoid

Posted: Sun Nov 19, 2023 4:44 pm
by paul williams
I was able to repair one for a P4 a few years back. The operation is the same. The coil was showing open circuit when tested, I decided to unwrap the coil to see how much wire was used and save it on another bobbin. Luckily I came across the 'break' quite soon, in fact only after a few turns were removed. I think the break was due to some kind of previous impact on the outside of the coil. Rewinding shouldnt be difficult, I have rewound large 12v relays before using a slow drill in a vice. After all there is nothing to lose. A 12v solenoid similar to the one you linked to could be made to work I am sure.

The main problems I have come across are the 'ball' not seating properly or the pick up tube leaking air. Both issues stop it working even if the solenoid is OK.

Re: Rewinding a fuel reserve solenoid

Posted: Mon Nov 20, 2023 8:32 pm
by David2021
I have taken the easy way out and taken my dismantled unit to Four Ashes Garage (who are a couple of miles from me). They have remade them for (primarily) DB Aston Martins ( and price the accordingly) They also do them to suit Rover, Bristol, Armstrong etc
I am nervouslwaiting for an estimate....😲

Re: Rewinding a fuel reserve solenoid

Posted: Tue Nov 21, 2023 5:57 pm
by David2021
Well, for a new solenoid, steel parts re-plating, pressure testing for cracks in the tubes, reassembly and test etc about £200!...
A new one is about £500 from them :shock:
Maybe a Christmas present to myself! perhaps a glass panel in the boot floor so it can be gazed at in wonder!
Luli said he just "took his to a local workshop who rewound the solenoid!" in Tel Aviv perhaps, but not round here!

Re: Rewinding a fuel reserve solenoid

Posted: Wed Nov 22, 2023 11:30 am
by RobHomewood
I am now confused when you talk about pressure testing tubes whether you are talking about the fuel sender unit with the main/reserve solenoid and dip pipes etc or the fuel level indicator with the moving arm and float. I have sourced both items (Lucas look alikes) for my P2 on the internet without too much trouble apart from some delay waiting for a container load to replenish stocks from USA. (Holden also supply the side mounted version of the fuel level indicator for the sump oil level indicator) The problem I had with the fuel and oil level indicator units was that they seem to develop a leak (petrol) around the arm bushes into the coil area and short out. I still havent worked out why there isnt a big bang but so far so good!
Rob

Re: Rewinding a fuel reserve solenoid

Posted: Wed Nov 22, 2023 11:36 am
by RobHomewood
PS Sorry I think I said Lucas when I should have said Smiths type units
Rob