Oil Pump rebuild (1 Viewer)

[Girl und Panzer]

Hey guys,
Been all over google and mud but can't find any instructions for this. is there a writeup I just can't find? I've got a good deal of mechanic experience so I think I can accomplish this, any advice or warnings appreciated. Was thinking of using this from cruiser parts. Is that really all I need parts-wise?

 

[Rivman1243]

Just out of curiosity why are you rebuilding it?

 

[Girl und Panzer]

Low pressure, a new one is apparently quite expensive

 

[Tools R Us]

I doubt the pump is your problem, what oil is in it?

 

[inkpot]

Has your power steering been weak also?

 

[Rivman1243]

Has your power steering been weak also?

What does the power steering being weak have to do with the oil pump rebuild? Sorry for all the newb questions. Just trying to learn as much as possible on these rigs

 

[Girl und Panzer]

My guage is suddenly reading differently (valvoline maxlife 10 40 synthetic blend, been running it for years though so I don't think that was it). If you consider the four marks as 1, 2, 3, 4, the normal reading was 2 at idle and 3 under power, now its 1 and 2 respectively. Inkpot, what is your correlation with PS? It hasnt been weak, I would say, although since the reading changed, I've had a few situation where when I was parking, I cut the wheel hard with the brakes on and not moving and stalled the engine. more than about 1 turn at idle and the revs drop by 1-200 too.

 

[inkpot]

Power steering pump and oil pump are both driven from a gear on the front of the crank shaft. That gear is NOT keyed onto the shaft. The gear is trapped onto the shaft by the front belt pulley nut being torqued properly to 309 # ft. If that nut is just kinda tight you can loose some or all of the oil pressure and power steering.

 

[Girl und Panzer]

Ah I see. is that the main crank pulley nut?

 

[inkpot]

Ah I see. is that the main crank pulley nut?

Yup

 

[inkpot]

Yup

Several rigs have have had complaints about one or the other and come to find out they ha be problems with both. PROPERLY torqued nut and both problems went away.

 

[inkpot]

How many miles on your engine. Not surprising for rigs with high mileage/ poor maintenance. Not necessarily a death knoll. Engine get looser and looser with age, so tolerances open up and oil flows easier. So less pressure on gauge, but it is still pumping good volumn. Lots of us in Arizona run 20/50 with good results

 

[Rivman1243]

I've been thinking that my oil pressure has been a little low once the oil gets hot. Ive also noticed that my power steering also seamed weak. I was doing some baseline maintenance and noticed that the power steering pump has a "reman" sticker on it. Sounds like I need to check the Torque on that nut

 

[bloc]

Realistically it shouldn't need to be at 309 to adequately clamp the gear and drive the pumps at full speed, but that is the spec torque and they have been known to run loose before, as mentioned earlier.

Depending on age and maintenance on your rig it is also possible that the heat exchanger in the oil cooler is sludged up, preventing it from actually cooling the oil. I'm pretty sure mine has this issue at ~290k as oil pressure drops somewhat and I can faintly smell burning oil from the exhaust when I'm working the truck really hard (deep sand for sustained period of time, etc). Othewise oil pressure is right where I'd expect it to be with a 0w-40.

I've halfway been experimenting with an IR temp gun on the oil pan in certain conditions, but far from being scientific about it. And probably not worth installing and routing an oil temp gauge.. I'll just try to find time to clean the cooler if I don't drop a vortec in first.

 

[4runnerd]

Hey guys,
Been all over google and mud but can't find any instructions for this. is there a writeup I just can't find? I've got a good deal of mechanic experience so I think I can accomplish this, any advice or warnings appreciated. Was thinking of using this from cruiser parts. Is that really all I need parts-wise?

Well, if you're gonna do a complete rebuild (and if you're going to take the thing apart, you really should be complete), then you're definitely going to need more than just the drive rotor. But, you may not even need to do the rebuild.

I would start by looking at the pressure sender; test it and see if it's working properly. If there are no symptoms beyond a difference in the gauge reading, you don't want to begin by tearing apart the oil pump- that's the very last thing that you want to try, not the first- it's quite a robust unit.

The stall from working the power steering that way seems to indicate an increase load on the engine that is causing it to stall. A loose crankshaft pulley would decrease the load under work.

By the way, how does your PS fluid look? This is an often overlooked system, and if the fluid is brown, try doing a complete flush to rectify the PS issue (it's supposed to be pink/red, as it is transmission fluid in there).

 

[Howard705]

Are more threads but- check pressure with a mech gauge to verify dash gauge. The rest of the motor bearings etc are usually just as worn out as the oil pump.

 

[bahamasair]

Get a manual gauge to verify pressure. There is also a pressure relief valve in the oil cooler and on the timing chain cover next to the oil pump that can get gummed up and stick open giving low pressure. When I rebuilt my engine I also found 5 of the 6 squirters that spray oil up under the pistons had the check valve stuck open. I'm not sure if it would make a huge difference in pressure but I changed them anyway.
I'd check the pressure manually before doing anything, the gauge is pretty crappy on the 80 if the tab the sender wire clips to rusts or gets crap on it your readings will be way off.
After rebuild I had the opposite problem, my pressure was too high and I was balooning oil filters. I double checked with the manual gauge and was getting 78 lbs at idle I went through everything to do with the oil system and never found a problem, I was using 10w40 to break it in and switched to a lighter grade oil and it's on the high side of the specs in the manual but within specs now. You can check wear on the oil pump with a feeler gauge but I'd bet there is nothing wrong with your pump.

 

[Girl und Panzer]

It happened as far as i know after i did a water crossing on a trail (correlation not causation that i can know for sure), oil change was a while before so wouldnt be a weight issue i think. its normal after cold starts. I'm going to try to torque that nut, i was pushing way too hard before the water and maybe the temp change somehow shocked it out of torque?

 

[2fpower]

I just bought a pump on amayama.com thought it was really cheap. Don't recall the price.

 

[inkpot]

Just measure the thickness of the impeller. Oil can pass by on the sides if it has worn down too much. I think the FSM has the tolerances allowable.