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LDA seal
Posted: 15 Sep 2017, 03:27
by Adeybruce
I've been leaking fuel from my JX engine's LDA. I have replaced the seal where the 'lever' enters the unit, but fuel still pours through.
Any ideas? Also is there anywhere that describes how the LDA works - I'm trying to understand how the how thing works and is adjusted. Thanks.
LDA seal
Posted: 15 Sep 2017, 07:44
by clift_d
Not sure what's going on here.
The LDA really has only two connections and neither is directly to the fuel system. One is a mechanical link to the injection system via an actuating rod that goes from the LDA to the boost lever on the head of the fuel injection pump. The only other connection to the LDA should be an air hose from a nipple on the intake manifold. The other port on the LDA is a vent and should be left open.
A silly suggestion perhaps but it might be worth checking whether somebody has connected the LDA into the injector leak-off system?
Re: LDA seal
Posted: 15 Sep 2017, 08:07
by mrhutch
clift_d wrote:
A silly suggestion perhaps but it might be worth checking whether somebody has connected the LDA into the injector leak-off system?
I was thinking along the same lines, but surely someone couldn't have done that???
There shouldn't be diesel filling the LDA!
Re: LDA seal
Posted: 15 Sep 2017, 08:22
by clift_d
mrhutch wrote:I was thinking along the same lines, but surely someone couldn't have done that???
There shouldn't be diesel filling the LDA!
Sherlock Holmes wrote:... when you have eliminated the impossible, whatever remains, however improbable, must be the truth.

Re: LDA seal
Posted: 15 Sep 2017, 23:54
by RogerT
My guess is the OP means fuel is coming from the boost lever seal, referred to by BW as a LDA shaft seal.
https://www.brickwerks.co.uk/t3-parts/e ... -seal.html" onclick="window.open(this.href);return false;
This?
If so, OP, did you use the BW part, or something else?
Re: LDA seal
Posted: 16 Sep 2017, 03:46
by Adeybruce
Thank you all for your replies, and sorry for my very poor description!
I think you got there - the leak is coming from the input shaft and yes I did replace the seal with the BW item.
I'm not sure of the mechanics of the system, but when I tightened the actuating rod to the bolt on the top of the input shaft there is still a lot of play. Maybe the excessive play is allowing for the leak?
Re: LDA seal
Posted: 16 Sep 2017, 06:41
by ZsZ
the parts inside the JX external LDA are the same as the standard ones with the tower. So there is a follower pin and a lever just like in a standard LDA and there is a small O ring at the pin so I think it failed too
Re: LDA seal
Posted: 17 Sep 2017, 16:22
by Adeybruce
That would seem to make sense, thank you
Re: LDA seal
Posted: 17 Sep 2017, 19:26
by doc.G60
there should be a washer/ shim on top of the blue seal too. You could always double up the blue seals? A bit of play is normal I think. Don’t over tighten it as the pin metal is quite soft and can snap.
Re: LDA seal
Posted: 17 Sep 2017, 23:33
by Adeybruce
doc.G60 - funny you should mention that, mine was missing the shim/washer. I solved the problem by doubling up on the seals (using the new one on the bottom, and the dried up crispy old one on top). Thanks for the reassurance that it was a good idea!