jhk Posted September 19, 2023 Report Share Posted September 19, 2023 Hi Forumers, To share my learning ... about a subject I have not found during searches on the TR Forum ... the reason will become obvious ... On the 2023 TR Ireland Spain trip (2500 km in ten days) last week I noted a fuel leak from the underside of the AC UE mechanical fuel pump (most probably original). We suspected bowl seal bedding in (new E10 resistant rubber seal installed prior to tour), and tightened the thump screw. Still a small leak, and left well enough alone till my return home. Once home, inspection with mirror/flash light showed that the leak was from a small hole in the lower body of the pump. Further inspection and Mr Google.... educated me about the vent/weep hole/tell tale hole. What a clever design I thought. One which would alert you to a failing diaphragm, before contaminating the oil in the block. My diaphragm (pic below) was indeed starting to fail. The rubber was coming from the backing material. Hence I wanted to share my learning.... I purchased a spare pump prior to the Spain Tour. Now educated about the vent hole... I inspected the new pump. NO VENT HOLE. I googled and found no other online UE retro pump on the market WITHOUT the vent hole. All the old pump bodies I have include the vent hole. I am in communication with my supplier to obtain a pump with the vent hole. I have attached photos for information. Quote Link to post Share on other sites
Z320 Posted September 19, 2023 Report Share Posted September 19, 2023 Hi XY, the drain hole works best with the rubber seal in the center of the pump, there where the push rod to the diaphragm goes through. You can see it below the steel retainer. Sadly you can’t buy them anymore, apart from somebody has a supplier. Ciao, Marco Quote Link to post Share on other sites
RobH Posted September 19, 2023 Report Share Posted September 19, 2023 Thanks for that Jim. This has been discussed before but the forum search function isn't very good so I'm not surprised you couldn't find it. The other things to note are that the cam arm on repro pumps is laminated from strips instead of being solid and has a smaller bearing area on the cam, and the pivot pin may not be secured properly, so can fall out. If possible it is far better to have an original pump re-built than to buy a modern repro one. Quote Link to post Share on other sites
jhk Posted September 19, 2023 Author Report Share Posted September 19, 2023 Txs Marco, You have a sharp eye. The above picture is from one of my old pump bodies. My pump body has a seal for around the diaphragm shaft... and thankfully is still a snug fit on the shaft. I will be very careful when reassembling the pump so as not to damage this oil seal. It is a press kit into body with a couple of peened in tabs. Oil seals can be obtained from Flexolite (qr below). Their site also has informative articles on these old pumps. Quote Link to post Share on other sites
jhk Posted September 19, 2023 Author Report Share Posted September 19, 2023 Thanks Rob for the lever pic. I have seen a number of discussions on the lever arm construction. My pump (which is stamped AC... patent pending) looks to have age. The lever is the riveted type. Contact point in pic below. The pivot is the through body type (thankfully) ... rather than the shaft pressed into the lower body casting arrangement. Pump was running fine (has been so for 13yrs in my ownership prior to this diaphragm leak). So will look to put it all back together as I found it ... I will start a separate chat on the pump/block seal selection... Quote Link to post Share on other sites
jhk Posted September 19, 2023 Author Report Share Posted September 19, 2023 Forumers... Do we know if Dave Davies is still working his magic on AC pumps in Manchester? I think I read he was having some eye surgery.... Do not want to call / bother him if he is no longer doing these refurbs... Txs Quote Link to post Share on other sites
Z320 Posted September 19, 2023 Report Share Posted September 19, 2023 Hi Jim? I‘ve been told most pumps fail because the lever slips off the cam because of too much play. This is why I shimmed the levers of my pump and the spare pump with bronze shims. Ciao, Marco Quote Link to post Share on other sites
rcreweread Posted September 19, 2023 Report Share Posted September 19, 2023 Dave Davies is back rebuilding pumps - I have sent you a PM with his contact details. However I would just re-iterate what I recently posted about "laminated arms" -AC Delco pumps were fitted with laminated arms when the TR4A was introduced - these arms have 3 laminations which are rivetted together. Dave Davies told me he had never seen one of these fail so don't ignore a genuine AC Delco pump with a laminated arm - it is a correct fitment for TR4As but its also perfectly acceptable to fit to earlier cars. Repro pumps copied the laminated option but very poorly with usually 2 laminations and these regularly fail. Cheers Rich Quote Link to post Share on other sites
Z320 Posted September 20, 2023 Report Share Posted September 20, 2023 (edited) One problem of the repro pumps seems to be the shaft. It is only pressed in with 2 clips and they can move out and fall into the engine - I've been told. I own one of the pumps (3 layers) as a spare pump and for safety I made "shim" to avoid this. A bit a poor idea, but the pump is good quality and for testing I used it for 1 summer (without shim). Ciao, Marco Edited September 20, 2023 by Z320 Quote Link to post Share on other sites
RogerH Posted September 20, 2023 Report Share Posted September 20, 2023 Hi Marco, I think it is a good idea. Recovering a poor design and making it safe. Roger Quote Link to post Share on other sites
Z320 Posted September 20, 2023 Report Share Posted September 20, 2023 Who ever had to change the pump next to the street dammed the rear upper nut. A friend with a lathe could make you this special loooong nut from a hex 1/2" bar And a fuel tap in the ingoing hose is also very helpful. Ciao, Marco Quote Link to post Share on other sites
Charlie D Posted September 20, 2023 Report Share Posted September 20, 2023 Brilliant idea Marco. It can take half an hour to get that nut off by normal means. Maybe another item you could make/sell to boost the money in your “Dinner out with the wife” bank account. Quote Link to post Share on other sites
mikej Posted September 20, 2023 Report Share Posted September 20, 2023 Having been recently engaged in a pourus diaphram "project" I learned that, while the "UE" AC pump part number allocated by Triumph did not change, the actual assembly did. For starters, the oil seal was added after Engine TS. 2074E - apparently to stop oil flowing through the vent hole on fast RH corners. It is a different casting, the recess hole changed size to accomodate it and is not retrofittable. Many TRs seem to have been subsequently fitted with lower pump castings that don't have the seal (or did Triumph fit them?). The oil seals I have seen are typically rock hard and/or breaking up thus providing a poor seal at best. They had not been available although they are now. All said, oil flow through the breather is not a common complaint? Fitting a slot type gasket may well help but as already commented, may reduce lubrication to the pump? Thickness of the gasket is moderately important. Very nice fixing bolt extension, now on my list! MJ Quote Link to post Share on other sites
Z320 Posted September 20, 2023 Report Share Posted September 20, 2023 1 hour ago, Charlie D said: Brilliant idea Marco. It can take half an hour to get that nut off by normal means. Maybe another item you could make/sell to boost the money in your “Dinner out with the wife” bank account. I'm afraid with this idea it will only be a packet of crisps, with some luck a quality producer Quote Link to post Share on other sites
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