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Perkins 6.354 fuel pump JCB 814

Posted: Wed Apr 25, 2018 11:15 pm
by essexpete
Dear all

I noticed today a diesel leak from what looks like a round disc (diaphragm) on the front side of the vertical fuel pump. Not sure what this does (some kind of regulation?). Is it common to develop a leak there? I can't see exactly from where the leak is actually coming.

Thanks Peter

Re: Perkins 6.354 fuel pump JCB 814

Posted: Thu Apr 26, 2018 7:05 am
by Jeremy Rowland
Pete what does this look like? I was wondering if it was one of the pumps valves? Are you sure the diesel is not running down to there from a higher place?

Jeremy

Re: Perkins 6.354 fuel pump JCB 814

Posted: Thu Apr 26, 2018 9:22 am
by essexpete
Jeremy Rowland wrote:Pete what does this look like? I was wondering if it was one of the pumps valves? Are you sure the diesel is not running down to there from a higher place?

Jeremy


Good point I shall have to clean it up a bit. I found a photo on the web, not all pumps appear to be fitted with it.

Thanks

Re: Perkins 6.354 fuel pump JCB 814

Posted: Thu Apr 26, 2018 10:06 am
by kaos
This got me intrigued enough to do a bit of googling. According to http://www.tadiesels.com/fuel_injector_acc.html , this is an "Injection Pump Damper".

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Regards, Kári.

Re: Perkins 6.354 fuel pump JCB 814

Posted: Thu Apr 26, 2018 10:29 am
by Jeremy Rowland
Okay now I know what we are looking at :thumbup: is it a bad leak or not? Pete I would have thought you would only get this issue fixed by an injection pump specialist?

Jeremy

Re: Perkins 6.354 fuel pump JCB 814

Posted: Thu Apr 26, 2018 10:31 am
by FOWLER MAN
essexpete wrote:Dear all

I noticed today a diesel leak from what looks like a round disc (diaphragm) on the front side of the vertical fuel pump. Not sure what this does (some kind of regulation?). Is it common to develop a leak there? I can't see exactly from where the leak is actually coming.

Thanks Peter

Hi Pete.
That roumd disk thing is a damper, part of the two stage advance and retard mechanism.
The unit avances and retards the injection timing according to engine speed and load , (stage one), and further retards the timing to assist cold starting, (stage two).
Some of the early DPA pumps I worked on,( fitted to David Browns), had a manual version opperated by a screw on the advance and retard unit.
There is a gasket between the unit and the pump body and four or five other seals / washers all of which I suppose may leak.
It's not difficult to replace them and pump overhaul seal kits are readily available for a few quid, (try ebay). Its the same kit for the mechanically governed four and six cylinder pumps.
Fred

Re: Perkins 6.354 fuel pump JCB 814

Posted: Thu Apr 26, 2018 10:45 am
by FOWLER MAN
Hi Pete,
I just dug this out of the manual, it may help?
Image

Re: Perkins 6.354 fuel pump JCB 814

Posted: Thu Apr 26, 2018 2:24 pm
by essexpete
Thank you very much for your reply. It is not a huge amount leaking at the moment but you would not want to spend the night underneath the old girl anyway! I will keep an eye on it now I know what it is. Funnily enough it had not been run for a couple of months at least with the warmish weather yesterday it fired almost instantly. It has done over 15k hrs and I don't think the engine has been touched. Tempting fate but I will change the oil.