Bobble Posted February 6, 2020 Report Share Posted February 6, 2020 (edited) Has anyone had issues with the vacuum pipe (part 12H733) that runs between the distributor and the carburetta via a cylindrical shaped vapour trap? The following information may help before you order a replacement. The connections for my SUs are female screw fitting at the distributor end and a push fit onto a rubber elbow at the carburetta. My pipe broke and I sent for a replacement from Moss UK. When it arrived the copper pipe that goes between the vapour trap (fixed to a bracket on the fuel pump housing) and the front carburetta was well short (around 5") and had no chance of reaching the carb - it needs at least 30cm (12"). I checked the part number and it was definitely the correct component - I also checked the Rimmer catalogue and obtained the same information. I rang Moss in order to get further advice. Adam in the parts department was extremely helpful and, following a lengthy discussion, emailed photos of my engine bay and measurement of various different pipes we came to a decision on how to proceed. At one stage I had considered obtaining a length of copper pipe (probably a good section of the old one) and soldering on a collar in order to extend the length. However, in the end Adam, after measuring the length of pipe extending from each side of the vapour trap, sent me part number 1H919 . Although it had screw fittings at both ends the lengths were correct and I was able to remove the olive from the carb. end and simply push the pipe into the rubber connector. Job done. I am posting this for two reasons. Firstly, it will hopefully save other members a fair amount of wasted time and secondly to comment on the excellent service received from Moss via Adam Chignell who was prepared to make a genuine effort to sort out my problem with a positive outcome. Thank you Bob Edited February 6, 2020 by Bobble Remove greeting Quote Link to post Share on other sites
james christie Posted February 6, 2020 Report Share Posted February 6, 2020 These things are notoriously unreliable. It’s not a vapour trap (at least on my 3A it wasn’t) It’s a vacuum unit with a membrane to retard things a bit if you floor the accelerator. If you set the bob weights up in the distributor appropriately you can do away with it - as I did some 20 years ago. james Quote Link to post Share on other sites
TorontoTim Posted February 12, 2020 Report Share Posted February 12, 2020 I've had two vacuum pipes fracture in use. Am I playing too roughly? Quote Link to post Share on other sites
stuart Posted February 14, 2020 Report Share Posted February 14, 2020 (edited) On 2/12/2020 at 9:27 PM, TorontoTim said: I've had two vacuum pipes fracture in use. Am I playing too roughly? If you have the ones that bolt on either end then that will be the problem, thats why the later cars ended up with a short piece of rubber connecting each end. You could introduce a piece between at either end to help. Stuart. Edited February 14, 2020 by stuart Quote Link to post Share on other sites
TorontoTim Posted February 14, 2020 Report Share Posted February 14, 2020 Thanks, Stuart - i will attack it in the spring Quote Link to post Share on other sites
stillp Posted February 14, 2020 Report Share Posted February 14, 2020 11 hours ago, stuart said: If you have the ones that bolt on either end then that will be the problem, thats why the later cars ended up with a short piece of rubber connecting each end. You could introduce a piece between at either end to help. Stuart. I always thought that was just to save money! Pete Quote Link to post Share on other sites
brenda Posted February 14, 2020 Report Share Posted February 14, 2020 Should you have and do you need this vacuum pipe? I have been running my 4a for 10 years with just plastic pipe running from carburettor to distributor. Mike Redrose Group Quote Link to post Share on other sites
stuart Posted February 15, 2020 Report Share Posted February 15, 2020 14 hours ago, brenda said: Should you have and do you need this vacuum pipe? I have been running my 4a for 10 years with just plastic pipe running from carburettor to distributor. Mike Redrose Group Thats fine, the capsule ones are TR ones anyway never have been. Stuart. Quote Link to post Share on other sites
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