how to? oil pump rebuild...

[Veepster]

hi guys!

I am sure a bunch of you have rebuilt the oil pump....what parts do I need and is there anything I should know that will make the job more successful?

thanks!



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Peace.............BartG

the Green Flash!
360 2v, TH400 QT with low
4" skyjacker Rancho 9000's
33x12.50 BFG KO's 8" American Racing Baja Rims
Thorley headers, 3" exhaust, Dyno Max
Infiniti power leather seats
50%Luxury Car, 50%Tractor
http://www.teamgodspeed.com

[angry joe]

Hey Veepster,

The problem I had was 10 psi for every 20 mph & no psi at idle.So I rebuilt my oil pump a month ago and it went really smooth.I bought the gears,psi relief valve and spring for only for 15.00. I Took a chance and didn't replace the housing.It was as simple as pulling out the old gears and installing new ones.Now I have 60 psi at highway speeds and 20 psi at idle.

If you need more specifics just ask. I hope I was some help.Refer to a Haynes book for more detail.

http://www.ifsja.org/ubb/mad.gif angry joe

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79 Cherokee
360 AMC/TH 400/QT
Eledbrock intake & carb
3" body lift
Hedman headers,
cherry bomb mufflers
Dual gas tanks

87 GW plain stock
360 AMC/727 trans/select a trac

"One mans trash is another mans treasure."

[reddog]

Set the clearance between the top of the gears and the cover on the tight side of the allowed tolerance to maximize pressure.

Kerry

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87 GW - Stock (but it looks like RiverBeast when I'm sleeping)
TFI upgrade
360,727,NP229

[stuart]

Veepster,

I just bolted mine back together not more than two hours ago. What I originally thought would be a quick operation took much longer.

I went to NAPA and asked for an oil pump rebuild for the AMC 360 and they gave me what I needed, cost if I remeber right was about $15. The kit consisted of the two gears, one of which was mounted on a drive shaft, a spring, pressure valve and gasket.

Things to consider when approaching this task. Have a Haynes manual on hand. Set aside a reasonable amount of time to overcome stuck parts. Get some parts cleaner or carburator cleaner, the varnish produced inside the timing cover made removal of the old gear/shaft a bear. I yanked on it for an hour only to pull it 1" out of the pump. What was necessary was removing the distributor (make sure you mark the position) and pounding the thing out from the top with a 12" #3 screwdriver. Even that was limited as I pushed the shaft to a point where the screwdriver blade was too wide and would damage the casting of the timing cover. At that point I went to Home Depot and bought a length of 3/8" steel rod to finish the job.

Overall it was not a bad job once I had the right tools, and the bit of advice about pounding the shaft out from the top (came from this forum!) I'll be starting the wag in the morning after praying to the oil pressure gods tonight.

Good luck

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<LI> 88 Grand Wagoneer 55K mi
<LI> Stock except...
<LI> Kenwood CD and speakers
<LI> Dupont Cherry Red Pearl paint
<LI> View my baby (http://albums.photopoint.com/j/ViewPhoto?u=1340994&a=10041302&p=33310327)

[Veepster]

thanks guys..!!!

My problem is.....when I start the FSJ it takes about 10 or 15 seconds for pressure to come up at all....after that it is perfect.....it has been gradually getting worse over the last few thousand miles....seems like a an easy enough job(now that you guys helped me out)........I will let you know if it solved my problem

------------------
Peace.............BartG

the Green Flash!
360 2v, TH400 QT with low
4" skyjacker Rancho 9000's
33x12.50 BFG KO's 8" American Racing Baja Rims
Thorley headers, 3" exhaust, Dyno Max
Infiniti power leather seats
Custom billet shift knob by Millerluck
50%Luxury Car, 50%Tractor
http://www.teamgodspeed.com

[BobBarry]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Veepster:
thanks guys..!!!

My problem is.....when I start the FSJ it takes about 10 or 15 seconds for pressure to come up at all....after that it is perfect.....it has been gradually getting worse over the last few thousand miles....seems like a an easy enough job(now that you guys helped me out)........I will let you know if it solved my problem
<HR></BLOCKQUOTE>

That sounds like the normal early-guage operation. The needle operates off a bimetallic arm that heats up to different amounts, depending on how much resistance the oil-sender offers, which allows it to heat up more or less. The guage is only as responsive as quick as that bimetallic arm can heat up or cool down. In cold weather, it can take a real long time for that arm to heat up, so it doesn't read properly for a while (like you say, 10-15 seconds). And when it does heat up, it's still not the most accurate instrument.

Unless your motor is clacking away during those 15 seconds, I wouldn't worry about it. If you are concerned, hook up a mechanical oil-pressure tester gauge to see what it reads immediately upon startup.

As people have said, those gauges are "for entertainment purposes only."

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Bob Barry<UL TYPE=SQUARE>* '78 Cherokee 4-door
* '88 Grand Wagoneer[/list]http://studentweb.providence.edu/~rbarry/wheels/

[Veepster]

thanks for the info BobB......but why does it get continually worse?...I am confused....and if I turn off the vehicle for a minute or so and then start it again it takes another 10-15 seconds again.....wouldn't that arm still be warm?.....aah what the heck, I got a new sender today and I will rebuild the pump, if it changes nothing, I will at least know I did all I can!....and THEN I will stop worrying!! thanks Bro!

[Veepster]

SUCCESS!!!

I changed out the sending unit and voila! oil pressure in about 2-3 seconds....

phew what a relief!.....I hate oil pressure guages in the red...

------------------
Peace.............BartG

the Green Flash!
360ci
Custom 4v TBI
Edelbrock Performer Manifold
TH400, QT with low
4" skyjacker Rancho 9000's
33x12.50 BFG KO's 8" American Racing Baja Rims
Thorley headers, 3" exhaust, Dyno Max
Infiniti power leather seats
Custom billet shift knob by Millerluck
50%Luxury Car, 50%Tractor
http://www.teamgodspeed.com

[andy d]

hi Stuart, long time no see. dont forget to pack the pump gears with petroleum jelly to get the prime going. good luck

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'88 gwag,pure stock

[stuart]

andy d,

Thanks for the welcome back, its nice to know my absence was noticed, what do I expect from such a great group of people on this forum?

Yup I packed the thing with jelly, in fact I ment to remind veepster of that and let him know to pack the gears before installing and pack the pump chamber at least 1/2 way too before installing. That way the stuff oozes out and insures adequate fill.

I was thrilled to start the wag up this morning for the first time in over a month. He had been sitting in the drive way with the oil pump cover off and the stuck shaft half way out. Things got busy around here with Christmas and all, travel etc and the only days I had free to finish the job were cold and rainy.

My maiden voyage with the rebuilt pump proved a success. Readings as follows; COLD, idle 50, city driving 55-60, HOT idle (city) 25, city driving 50, HOT idle (after hiway) 15, 50 on the road. I'm so relieved to have these readings after the 0-6 hot idles I had pre rebuild. I was sure that the rebuild would only confirm that I needed an engine rebuild, not so! Oh the things I can spend the $2000 on! Glad I didn't tell the wife about the impending doom, she might not have spent the money on my 40th b'day next weekend!