Fuel in sump

[MikesDexta]

I changed the oil in my 1959 Dexta last autumn, fully draining the old and putting in exactly the amount specified in the manual. It ran fine after this and the dipstick reading was on Max. I haven't used it over Winter and forgot to close the fuel tap

In readiness for a bit of topping I've started it and it revved like hell, chucking black gunk out of the exhaust all over the place. Pulling the stop lever did nothing but then it suddenly slowed down and I managed to stop it. I then checked my engine oil level (several times) and its way past the full mark, almost to the collar so it looks like I have diesel getting into the sump. Having read a couple of posts on the subject how do I check the lift pump and injector pump seals etc. what do I look for? Do I have to replace the whole unit if I find a fault?

I plan to drain the engine oil tomorrow so I can check for diesel, but thought I would ask advice in advance.

thanks

Mike

[mathias1]

On a major it could be the fuel return pipe or a faulty fuel lift pump

[MikesDexta]

Thanks Mathias
I put 6.8 litres of oil in last year and when I drained the sump I got over 12 litres out, smelling heavily of diesel. I then removed the lift pump and took it apart. It was very dirty
IMG_20190706_130720-684x912[1] by Michael Jones, on Flickr

IMG_20190706_130737-684x912[1] by Michael Jones, on Flickr

I cleaned the diaphragm but for the life of me couldn't see any splits

IMG_20190706_131015-684x912[1] by Michael Jones, on Flickr

Any advice on what to do next would be really appreciated. Should I replace the lift pump anyway and what else can I check?

thanks

Mike

[MikesDexta]

Just an update, I removed, checked and blew out the return pipe from the injectors to the tank and also blew out the internal pipe in the tank and they were all clear.

I then went back to the lift pump and spotted that there is no fibre oil seal, absolutely no sign of it. I re-read the manual and it definitely says there is one!



None here either


and a lot of gasket sealer on the lower pump body



So I will order a new lift pump tomorrow and hope that this fixes the problem but first I will put more diesel in her and leave the sump plug off overnight with a pan underneath to see if there is still a leak. If not I will fill up with oil and give it a go unless someone can give me some cautionary advice?

My worry is that if it is the missing fibre seal and I have never touched the lift pump until today, then what damage could it have caused over the years since the engine rebuild? I will be fitting an oil pressure gauge this week as soon as my NPT Tee arrives.

[mathias1]

So I will order a new lift pump tomorrow and hope that this fixes the problem but first I will put more diesel in her and leave the sump plug off overnight with a pan underneath to see if there is still a leak. If not I will fill up with oil and give it a go unless someone can give me some cautionary advice?

My worry is that if it is the missing fibre seal and I have never touched the lift pump until today, then what damage could it have caused over the years since the engine rebuild? I will be fitting an oil pressure gauge this week as soon as my NPT Tee arrives.

Mike, it's a good idea to install a new lift pump and go from there. if it was leaking while it was standing still, that's probably caused by a faulty lift pump. I've seen in the manual that there's also a seal between the injection pump and the engine. That would be the next place to look into, if the problem isn't solved yet by replacing the lift pump.

[MikesDexta]

Many thanks I will order it 1st thing tomorrow and fit it Tuesday so by Weds I should hopefully know if I've fixed it so I will let you know how I get on.

[mathias1]

Many thanks I will order it 1st thing tomorrow and fit it Tuesday so by Weds I should hopefully know if I've fixed it so I will let you know how I get on.

Ok Mike, good luck!
I rebuilt mine using a "repair" kit. Wasn't a big job. Although putting on a new one is an easy and fast job.
viewtopic.php?f=2&t=7733&p=54504#p54504

[MikesDexta]

Hi Mathias
Someone else suggested the lift pump but alas it wasn't but after trawling the forum again I found a couple of topics covering the possibility of fuel leaking from the primer to the air manifold so I dismantled the manifold today and diesel trickled steadily from the heater fuel pipe when I disconnected it and then poured out of the manifold when I unbolted that. That's from overnight with the primer turned off! I've ordered a tap to fit between the pipe and manifold.

While I'm on I have a suggestion and you may have already considered this, but could we have a section covering Known Problems and Fixes?

I'm just conscious that an awful lot of known problems are repeated as new enthusiasts join, and I can almost hear the more experienced amongst us groaning and saying 'it's already been covered, umpteen times - do a search!' However an awful lot of valuable information is contained in various discussions and restoration stories that are very useful and enjoyable to read but tricky to quickly eek out a solution to an immediate problem.

I'm sure my particular problem comes under the 'Black Gunk From Exhaust' title and solutions could be the primer fuel leak and possible faulty lift pump. Someone else (Alex) is just about to rebuild his steering column which has been covered many times on the forum but just needs a step by step approach perhaps? I think something like this may benefit from an approval process before posting to avoid clutter and ensure technical correctness, so is it possible to have some sort of technical sub-group?

Just my thoughts

thanks

Mike

[mathias1]

Hi Mathias
Someone else suggested the lift pump but alas it wasn't but after trawling the forum again I found a couple of topics covering the possibility of fuel leaking from the primer to the air manifold so I dismantled the manifold today and diesel trickled steadily from the heater fuel pipe when I disconnected it and then poured out of the manifold when I unbolted that. That's from overnight with the primer turned off! I've ordered a tap to fit between the pipe and manifold.

While I'm on I have a suggestion and you may have already considered this, but could we have a section covering Known Problems and Fixes?


I'm just conscious that an awful lot of known problems are repeated as new enthusiasts join, and I can almost hear the more experienced amongst us groaning and saying 'it's already been covered, umpteen times - do a search!' However an awful lot of valuable information is contained in various discussions and restoration stories that are very useful and enjoyable to read but tricky to quickly eek out a solution to an immediate problem.

I'm sure my particular problem comes under the 'Black Gunk From Exhaust' title and solutions could be the primer fuel leak and possible faulty lift pump. Someone else (Alex) is just about to rebuild his steering column which has been covered many times on the forum but just needs a step by step approach perhaps? I think something like this may benefit from an approval process before posting to avoid clutter and ensure technical correctness, so is it possible to have some sort of technical sub-group?

Just my thoughts

thanks

Mike

Mike, I'm glad you have sorted it out. Anyway it, seen the condition of the fuel lift pump, you did a great job replacing it also.
We have been thinking about making a place for the most common problems and solutions.
Lately we installed a subforum Owner and Repair Manuals, where jpegs can be attached to the post. Is someone wants to cover a problem and solution, it can be used that way. So feel free if you want to make some textbook work about a specific problem and it's fixes. It could be as simple as installing new brakes.

[MikesDexta]

You wouldn't believe this but after the Dexta has been running clean for a month or more (no smoke or black gunk) I went to start her and there was a large pool of diesel under her despite the fuel tap on the primer being screwed closed! It was dripping from the gauze filter in the (new) lift pump and the fuel pump drain pipe; so I then checked the dipstick and again the crankcase is full of diesel! I then syphoned off the remaining fuel in the tank and the drips stopped

I checked the new tap on the air intake end of the primer pipe and it was still switched to off, so tomorrow I will disconnect it to see if diesel is getting through. If so there will be 'weeping and gnashing of teeth' followed by a stiff conversation with the supplier of said tap, another 7 litres of oil wasted and as usual it always happens when you really need your tractor, I have 4 acres of topping to do

[Old Hywel]

I remember the sump filling with diesel, many moons ago. Fiddled with the lift pump and the injection pump drain, all to no avail.
The culprit turned out to be the fuel primer (as above). The jet in the inlet manifold was originally sealed by a spring-loaded ball bearing, the replacement was a more robust brass tap.

[MikesDexta]

Done all that and it seemed to work as she started and ran really well for a month, then suddenly it filled up again. I checked again this morning and the tap is definitely turned off so I removed it and this happened

https://youtu.be/GBVgs-DQkf4

I can only assume that the new tap is faulty, it came from the Land of Nearly Right via a local distributor and took ages to arrive when other parts have arrived within 2 days which is suspicious. I'm now off to the distributor to sort it out as I can't see how fuel could get into the air intake other than via this bloomin tap.

Any ideas gratefully received

Mike

[MikesDexta]

I didn't make it to the Distributor as I spotted a slight leak from the bottom of the tank, so I removed it and found a pinhole. So now I have to seal the tank and plan to use POR15.

There was also a slight leak from the primer pipe union to the primer pump despite it being fully tightened. I've bought 2 of these primer pumps now and both have been rubbish due to poor quality threads, and so is the new primer fuel tap as the lever is so loose it could easily open under vibration. When I bought her she had a standard tap (no primer pump) and no primer feed pipe tap an the air manifold, but that could never have worked properly and I suspect that years of Easy Start had wrecked the engine as it badly needed rebuilding.

I am at the end of my tether with this primer system, not only is is a poor design but the replacement parts seem very poor quality. so I'm now seriously contemplating fitting the primer pump replacement system from Old Tractor Parts that will do away with the primer pump and manifold tap.

https://old20tractorparts.com/dexta/297 ... 10206.html

Does anyone have an advice before I take the plunge?

thanks in advance

Mike

[Mervyn Spencer]

Hi Mike, I'm sorry to hear of all your issues you are having with that primer pump. Unfortunately this has been an ongoing issue for many years now, I believe most part replacements are made in Asia, shout me down if I am incorrect. Would the supplier of the kit you have shown a link to be prepared to take the kit back if it also malfunctioned? Which part of the world are you from Mike?

[MikesDexta]

Hi Mervyn
Yes it is a real pain and I will be returning the parts. I live in the Northamptonshire, England.

Mike

[Mervyn Spencer]

Well Mike I trust that you will succeed in the end, hope it don't take too long. Thank you for your place of residence must be a lovely part of the world, I just find it so interesting to read which part of the world members live.
Mervyn.

[MikesDexta]

Just an update on my fuel syphoning problem, since I removed the primer pump and feed pipe I have had no black gunk, no scary starting and absolutely no fuel in the crankcase and she starts on the button with no smoke so I'm definitely going to fit the thermostarter mod ready for winter.

To add to my progress, the charging problem was the dynamo. The old dynamo was motoring and had a charging output at one point but this proved to be intermittent as there was none the last time I checked (and I flashed the field coils more times than Flash Gordon). Anyway, I swapped out the dynamo today and the charge lamp dimmed and went out at 1200 rpm

I also fixed my handbrake pawl; I thought it was broken but it just turned out to be seized so a few squirts of Plusgas and a wiggle with a large pair of adjustable pliers and it now works.

I'm now left with:
A slight clacking on idle that may be the water pump, well that's what i'm telling my councillor; there's a monkey on my shoulder whispering 'I bet it's the crank'..

A small diesel leak from one injector leak off so I need 6 new copper washers as I've never replaced these despite taking out the injectors several times. The Land of Nearly Right (nice dynamos) don't sell them so I need to order from another supplier.

Mike