Getting to the Oil Pump
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
Getting to the Oil Pump
My '79 has got some very low oil pressure and I want to examine the Oil Pump. Do you have to remove some of the steering stuff to be able to drop the oil pan?
(yes i have tried a new sensor and changed oil and filter)
(yes i have tried a new sensor and changed oil and filter)
Pro
Joined: Nov 1999
Posts: 520
Likes: 5
From: Front Range
How low is the oil pressure? Examining the pump will involve breaking the oil pan seal, and I can say from all the guys that have tried it in the hotrodders forum, almost 75% end up pulling the motor to fix something afterwards. It is very difficult to get at the back main oil pan bolts with the flexplate / flywheel in place, not to mention applying RTV properly to a clean enough surface to re-seal the pan.
Be very careful about dropping the pan on an engine that is otherwise running okay. I'd suggest ruling out all other problems before pursuing this solution. Have you checked your oil pressure sender line? gauge?
let us know what you find
the blonde weasel
Be very careful about dropping the pan on an engine that is otherwise running okay. I'd suggest ruling out all other problems before pursuing this solution. Have you checked your oil pressure sender line? gauge?
let us know what you find
the blonde weasel
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
When cold started the gauge reads at the first mark- 20psi
As it gets warmer it reads around 10 psi and doesn't really go up with RPM.
The engine seems to run fine and does not smoke. Is it really that bad to get to the oil pump?
As it gets warmer it reads around 10 psi and doesn't really go up with RPM.
The engine seems to run fine and does not smoke. Is it really that bad to get to the oil pump?
Racer
Joined: Aug 2000
Posts: 488
Likes: 0
From: Fremont,CA
Originally Posted by 79vetter
When cold started the gauge reads at the first mark- 20psi
As it gets warmer it reads around 10 psi and doesn't really go up with RPM.
The engine seems to run fine and does not smoke. Is it really that bad to get to the oil pump?
As it gets warmer it reads around 10 psi and doesn't really go up with RPM.
The engine seems to run fine and does not smoke. Is it really that bad to get to the oil pump?
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
Originally Posted by 79vetter
Is it really that bad to get to the oil pump?
1) Remove flexplate/flywheel cover. You may have to pull the oil filter for access to the bolts and you will have to pull the starter. I trimmed my cover so I could pull it without removing the starter.
2) Break the steering linkage loose at the idler arm. This will allow the steering linkage to drop enough to remove the oil pan.
3) Drain the oil pan then put the drain bolt back in.
4) Remove the oil pan bolts and remove the pan.
5) The oil pump is attached to the rear cap with one bolt. When you remove the oil pump, the oil pump drive shaft will drop out. Just make sure you reinstall it before you bolt the new pump on.
6) Reinstallation is the reverse of removal. Couple of tips.
- Use one of the new Fel-Pro one piece gaskets. This will cure leaks.
- I replaced my oil pan bolts with ARP studs. This makes it very easy to stick the gasket up, then put the pan on. Then, I just have to thread nuts on studs vice trying to feed a small bolt through the pan and gasket into the block. I tighten hand tight, criss cross from the center out and then repeat. The torque spec is like 7 ft-lbs on the small bolts and 15 on the larger corner ones. I just hand tighten since the Fel-Pro gasket has steel crush washers built-in . Result=NO leaks.
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Drifting
Joined: Oct 2004
Posts: 1,496
Likes: 1
From: Lafayette Louisiana
I agree with indigo. If you recently worked on an area where debris could have fallen into the pan and clogged up the screen on the pump, or if you had good pressure last time you ran the engine and today it is low I would be thinking maybe pump or screen. If this has been going on for a while then I bet you have other problems such as main bearing, cam bearings, rod bearing wear etc., basically its time to rebuild. Sure the pipe can come off the pump but you can overfill the crankcase with oil to check for that. If you try that I would run it long enough only to satisfy the test. If you have checked all wire/tubes, senders, gauges, not worked on the engine, and tested by overfilling I would go ahead and pull the engine out of the car. You will spend 2-3 hours on the pan job and may pull the engine anyway which is a 4-5 hour job; less than that for some. Or you could just run it until she dies which gives you a very good excuse to rebuild or replace. Good luck.
Race Director
Joined: Dec 2000
Posts: 10,896
Likes: 2
From: CO
Pulling the pan is quite easy. I think putting the car on jackstands is about the most difficult.. 
.. Get teh 1 piece felpro gasket and your set. Although I haven't ran mine after I have done some work to it so I may have a waterfall of oil waiting for me! 
I have read that low pressure is rarely caused by a pump. There is no pressure usually because there is no resistance left in the engine = worn out. Although you never know.
.. Get teh 1 piece felpro gasket and your set. Although I haven't ran mine after I have done some work to it so I may have a waterfall of oil waiting for me! I have read that low pressure is rarely caused by a pump. There is no pressure usually because there is no resistance left in the engine = worn out. Although you never know.
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
On my '79 the exhaust is not blocking the oil pan so no problem there.
The steering is the only thing blocking it. Dumb question: which one is the idler arm and which bolts need to come out?
The oil pressure shows about 5 psi when idling warm but the car seems to run well.
What is the "fill the crankcase with oil" test about?
So you are saying that the oil pump is unlikely place to look for low oil pressure?
The steering is the only thing blocking it. Dumb question: which one is the idler arm and which bolts need to come out?
The oil pressure shows about 5 psi when idling warm but the car seems to run well.
What is the "fill the crankcase with oil" test about?
So you are saying that the oil pump is unlikely place to look for low oil pressure?
Drifting
Joined: Oct 2004
Posts: 1,496
Likes: 1
From: Lafayette Louisiana
Some times the tube with the screen can be dislodged causing the pump to not pick up the oil from the bottom of the pan. You can over fill the crankcase slightly to see if the pressure improves. If this test works drop the pan. If not, either enjoy the car until it dies or pull it and rebuild/replace it. If you pull it now you may salvage the crank if you keep running at low oil pressure you may have a heavy boat anchor. Make sure you have covered everything "outside" the engine first. I have seen way more worn engine bottom ends than oil pump problems.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Here is the steering linkage and exhaust pipe dismantled.
In my case it was not a bad pump but a round-to-it job for leaky front and rear seals. While everything is apart why not change most of the routine seals/gaskets/parts (e.g. oil pump, GM timing chain with nylon teeth, etc.)? After 20+ years things do start to wear/deteriorate.
In my case it was not a bad pump but a round-to-it job for leaky front and rear seals. While everything is apart why not change most of the routine seals/gaskets/parts (e.g. oil pump, GM timing chain with nylon teeth, etc.)? After 20+ years things do start to wear/deteriorate.
Last edited by Paul L; May 28, 2005 at 06:23 AM.
