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MG TD TF 1500 - No oil pump pressure

Hi guys
Engine rebuilt, and now I have added the oil pump. This has had new parts installed bushes cogs and shafts. However when turning the car over there is no pressure at the dial or even comming up the tube. There is a little play in the cogs and I appear to be missing the spring ball and other parts in the attached picture. My question is. Do I need these parts, they wernt in the Edney rebuild kit and didn't appear to be there originally although I did dismantle this 30 years ago.
How worn does a pump need to be before it stops pumping. Should it be full of grease or have I primed it incorrectly.
Any suggestions gratefully received.
Thanks in advance
Darryl


Darryl Lamb


Darryl, If your oil pump is the early type with a separate vertical filter, it should have the parts shown in your image. However, if it is a newer version with a integral horizontal filter, those parts aren't needed because the bypass valve is built into the pump cover.

The most common mistake during a rebuild that causes no oil pressure is mistakenly installing the wrong side oil pan gasket and covering the pick up tube hole. If the hole is covered, obviously oil can not be drawn up to the pump intake. These gaskets look similar, but if they are swapped around left for right, the hole will be covered?
Richard Cameron

Do fill your oil pump with petroleum jelly, which creates enough suction for the pump to prime. There are also many other techniques, including the never-fail garden sprayer, all described in great detail in the archives.

There WILL be oil pressure, eventually.

Tom Lange
MGT Repair
t lange

Darryl,
make sure you have fully primed the filter housing, fill the pump body at the priming plug (fig A36 WSM).put the car in gear and push back which will prime the pump.
Make sure the spark plugs are out and spin up on the starter, it may take some time. As Tom says it will come up.
Don't worry, I panic every time I rebuild an engine.
Ray TF 2884
Ray Lee

Many discussions on the forums on this.

If all else fails:

Jack up the left rear tire, remove the spark plugs, shift to fourth. Pour oil into the large port on the pump as someone turns the tire backwards. This turns the engine backwards, priming the pump.

Worked for me, took about 7 rotations.
MAndrus

If you are going to use any technique that rotates the engine backwards, i.e., counterclockwise, don't bother packing the oil pump with petroleum grease. It becomes ineffective with the first moment of backwards rotation. Bud
Bud Krueger

Use the garden sprayer method - easy to do, costs very little and avoids the need to fill the pump with Petroleum jelly.
Dave H
Dave Hill

Thanks guys for all the help...so in essence these pumps do mostly work after a rebuild even with a bit of play in them.
The garden sprayer method sounds interesting....will I find this discussed in the archives?
Darryl Lamb

Yes. Get a pump sprayer from B&Q or equiv. Ditch the spray end and fit with a connector to join where the capillary goes to the pressure gauge, Fill with oil and pump it up. It fills the galleries and the pump from the wrong side. Remove the pump, refit the capillary, then remove the rocker cover, and crank the engine with the starting handle until oil bubbles out of the rockers, then you are good to go. Check the oil gauge when you crank on the starter and you should get pressure immediately,
Dave H
Dave Hill

Thanks Dave I will give it a go....appreciate it and all the other advice.
Darryl Lamb

I agree with Dave H. above...with one caveat. When you first crank over the engine do it with the key off until you see oil pressure building on the gauge. When you see that it's safe to start the engine.
Gene Gillam

I didn’t have Vaseline but did have Lucas assembly lube which seemed like it would be thick enough and it was. Got pressure almost instantly. Besides with the Lucas name what could go wrong??
J Cosin

Darryl,

To answer your first question, the ball & spring assembly you showed is the filter bypass (it is not the oil pressure relief valve). Do you really need it? Let me ask this, do you really need an oil filter? Without those parts, most all of your oil will run unfiltered right into the engine (bypassing the oil filter). It is there in case the oil is very cold/thick or the filter is too restrictive.

That filter bypass is there to open if the pump pressure is much higher than the pressure in the oil gallery; that extra backpressure would be the result of oil filter resistance. It will allow oil to bypass the filter so as not to starve the engine of oil because it could be short circuiting back into the pump inlet via the oil pressure relief valve.

I recently primed an engine by siphoning in a quart of oil overnight. My main objective was to make sure everything was oil soaked before rotating. Oil even came out the rockers. The next day, I rolled it over backwards about 3 revolutions, hit the starter, and it jumped to 45psi in a few seconds. Note, pushrods and plugs missing. The trick is to find fittings suitable to attach a hose to the oil circuit.


JIM N

Jim,
Darryl's car is a TF with the later pump with the bypass built into the pump body and not the block.
Ray Lee

Thanks Jim and Ray. I'm assuming my pump at this point doesn't need bypass mentioned.
Think also I will try vaseline or grease as well as try to get oil down the tube to the gauge.
Out of interest I don't have the distributer or petrol in the tank or for that matter the wiring loom connected to the battery. Just trying to get oil pressure and the reconditioned engine turning over.
I will let you know how it goes.
As there has been no comments in terms of these pumps not working due to wear etc I will assume they are pretty robust. This was my engine builders concern.
Thanks again.
Darryl Lamb

Did you check the face plate was flat and free from wear marks - usually circular grooves from the end of the rotors? Its a good idea to do it to reduce internal leakage. I used fine wet and dry on a sheet of plate glass. Take care not to overtighten the long bolts as they are easily broken. Having done that and the other things you mentioned, you should have enough pressure.
Dave H
Dave Hill

Thanks Dave we got the face resurfaced. I was disappointed to find the new bolts I got with the rebuild kit were 5mm too short. Now have a combination of old and new. Think I may just use the old and wire them 😊
Darryl Lamb

This thread was discussed between 07/05/2018 and 09/05/2018

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