Diesel bomb failure

Hello, I have a Renault Express with a Lucas injection pump, and the problem is that during periods of overpressure in the pump (for example, during a cold start), the pump leaks fuel from the pump body. I suspect it's the gasket inside the pump, but I'd like to know if anyone else has experienced this and if they could confirm. I'd also like to know if I can replace the gasket myself or if I need to take the pump to a specialist. Thank you very much for your help, I look forward to your reply.

Hi pedro1981, I don't know if it's leaking from the cover, the throttle shaft, or the toothed pulley shaft seal. In any case, if it's from the cover gasket or the throttle shaft, it's relatively easy as long as you're handy with the springs and pay close attention to their position, especially on the advance lever located under the cover. Be careful with this lever, as its position can be confusing. Once you have it lifted, you can change the throttle shaft O-rings, but check if there's too much wear on the cover (the hole is conical). Then change the cover seal and you're done. But if it's leaking from the pulley shaft, I'm telling you, you have to be very precise. I've done it, but you have to take a hell of a job disassembling it, and you need to be very hygienic, not just clean... It's complicated if you haven't done it before, but there's always a first time, especially if it's for yourself. If it's already broken, go for it, you've got nothing to lose.

Hey, thanks a lot for the reply. A couple of fire engine mechanics I consulted told me it's a problem with the additives in the new fuels, and that I need to replace all the pump seals. So I have to open it up, calibrate it, and then put it on a test bench. They're asking €320, and honestly, I don't have the money and I'd like to tackle it myself. Do you know of any online tutorials that could guide me? I have some mechanical knowledge, so if I have some help, I feel capable of doing it. Thanks a lot for your help, and if you know of any tutorials, I'd really appreciate it.

Hi pedro1981, don't believe the additives. All they do is mix the diesel with biofuel, lowering the cetane number and "adulterating" it. Regarding pumps, there isn't much information available; it seems like classified material and hardly anyone teaches about it. What I did was download a Lucas CAV parts manual for a DCP; it only shows the location of the parts, which is sufficient. I advise you to only replace the ones on the cover, but the cover usually wears out due to friction from the shaft. If you can, get one from a junkyard. As for the pulley seal, I know someone who preferred to replace the engine. He told me it was cheaper than repairing it at Bosch. This seal almost requires complete disassembly, and that's where you can really mess things up, both because of the tricks involved and the need for precise cleaning and adjustments that you might miss. Make sure it's not leaking from there and that it's not staining the timing belt. So, there would be play in the internal bearing, and this isn't for just anyone... go for the cover, the O-rings are only €1.50 and you don't even need to remove it from the car