oil press WAY TO HIGH during prime

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360moparjunkie

360moparjunkie

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Priming oil system with drill on low speed and gauge soars past 160psi. The gauge I'm using I had on old motor so I mostly trust it. Gauge on old motor never went over 50lbs.

Now oil is leaking from oil filter. Thinking press damaged the filter causing it to leak. Drill barely turning runs gauge up to 70-80psi.

Whats the problem??? Oil pump is not bypassing....correct?

I did shim the by pass spring up 1/4-5/16"using a nut for a shim. No I did not put shim on wrong side of spring. Could I have reversed the by pass piston in front of the spring causing this condition?

Whats going on???
 

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That's WAY too much for a shim. Take it out.
 
RustyRatRod said:
That's WAY too much for a shim. Take it out.
Click to expand...

I am using a standard melling mv72 oil pump. Not a high volume pump......It is not by passing AT ALL.

How much shim below the spring should be used to increase pressure.

Is the small piston with the bypass holes in front of the spring directional? I could not tell when I replaced it. It did not appear to have a front or back the best I could tell.

What is the standard bypass pressure?
 
I have no clue. But all I have ever used is thin washers and never on a new pump. Why would you feel you need to increase pressure on a new pump with a new build? The stock pump is way more than sufficient. Leave the thing in there, I don't care.
 
If you wanted higher pressure, why didn't you just use the high pressure spring kit from Mopar Performance?

sometimes the "home fixes" don't fix... they make problems....


By "bypass" are you referring to the pressure relief spring?

Typical pump pressures are 45-75 psi (normal steady state running)

With the high pressure spring, I have had most run 55-75, and one or two up to 100 psi...



As far as the spring/valve assembly, do you need me to take one apart and get some pictures for you???
 
360moparjunkie said:
I am using a standard melling mv72 oil pump. Not a high volume pump......It is not by passing AT ALL.
Click to expand...


You may have gotten a chip or burr in there and the pressure relief valve may now be stuck, or not able to move like it's supposed to.

All it takes is one metal chip to get you in trouble... :banghead:
 
RustyRatRod said:
I have no clue. But all I have ever used is thin washers and never on a new pump. Why would you feel you need to increase pressure on a new pump with a new build? The stock pump is way more than sufficient. Leave the thing in there, I don't care.
Click to expand...

Its looking like my modification is the culprit. I read somewhere it was a worthwhile mod to gain a few extra psi. This pump mod is clearly uncharted territory for me. I will research better on the next one.
 
Karl. Read what he wrote. He has shimmed the spring either 1/4" or 5/16". That's TENMILES worth of shims. The bypass valve is probably not even able to move.
 
360moparjunkie said:
Its looking like my modification is the culprit. I read somewhere it was a worthwhile mod to gain a few extra psi. This pump mod is clearly uncharted territory for me. I will research better on the next one.
Click to expand...

It is, but you only add very thin shims. That's all. I would add nothing on a new build.
 
RustyRatRod said:
Karl. Read what he wrote. He has shimmed the spring either 1/4" or 5/16". That's TENMILES worth of shims. The bypass valve is probably not even able to move.
Click to expand...


I know.

I have a couple of HV pumps handy and was going to do a How-to for people who want to increase the pressure properly and use the Mopar Performance High Pressure Spring Kit.


Oil pumps and relief valves should not be messed with if you are not familiar with them.... #-o

It can get you in trouble.... :banghead:


But if it would help him, I could take one apart and install the spring and take pictures in the process....
 
krazykuda said:
If you wanted higher pressure, why didn't you just use the high pressure spring kit from Mopar Performance?

sometimes the "home fixes" don't fix... they make problems....


By "bypass" are you referring to the pressure relief spring?

Typical pump pressures are 45-75 psi (normal steady state running)

With the high pressure spring, I have had most run 55-75, and one or two up to 100 psi...



As far as the spring/valve assembly, do you need me to take one apart and get some pictures for you???
Click to expand...

I may just put it back as it was. Cost. Cost of spring kit was almost as much as a new pump. I was being cheap and am paying the price for corner cutting and shade tree re-engineering.
I hope returning it back corrects it all.
 
360moparjunkie said:
Its looking like my modification is the culprit. I read somewhere it was a worthwhile mod to gain a few extra psi. This pump mod is clearly uncharted territory for me. I will research better on the next one.
Click to expand...

Yep, your modification bit you this time... :eek:ops:
 
krazykuda said:
I know.

I have a couple of HV pumps handy and was going to do a How-to for people who want to increase the pressure properly and use the Mopar Performance High Pressure Spring Kit.


Oil pumps and relief valves should not be messed with if you are not familiar with them.... #-o

It can get you in trouble.... :banghead:


But if it would help him, I could take one apart and install the spring and take pictures in the process....
Click to expand...

Any additional helpful info would be appreciated. Pics or otherwise. This is the only pump I've modified. I want to do it correctly.
 
360moparjunkie said:
I may just put it back as it was. Cost. Cost of spring kit was almost as much as a new pump. I was being cheap and am paying the price for corner cutting and shade tree re-engineering.
I hope returning it back corrects it all.
Click to expand...


Where are you shopping???

Either you are getting oil pumps real cheap, or they are trying to rip you off on the spring kit...


Spring kit - $7.00

http://www.manciniracing.com/mopslan6brbh.html


Oil Pump - $49.00

http://www.manciniracing.com/318340360.html


So now you have a potential serious problem that could have been avoided by spending $7 on the proper spring kit..... Was it worth saving $7???

You need to calculate the risk vs the savings to see if it is worth it....


Trying to save a couple of bucks can come back and cost more than that....
 
360moparjunkie said:
Any additional helpful info would be appreciated. Pics or otherwise. This is the only pump I've modified. I want to do it correctly.
Click to expand...


Ok. Give me some time to tear it apart, take pictures, process the pictures, and then post them...

I'm on it...

Stay tuned...
 
Here's the thing. It takes a VERY small amount shimming the relief spring to make a BIG difference. That's why your 1/4" or so is really overkill. The difference between the standard and high pressure spring is a really small one in terms of lookin at it, yet it makes a big difference.

Look at the bright side. You're SMART. You stopped and ASKED before proceeding. It could have been a lot worse.
 
RustyRatRod said:
Here's the thing. It takes a VERY small amount shimming the relief spring to make a BIG difference. That's why your 1/4" or so is really overkill. The difference between the standard and high pressure spring is a really small one in terms of lookin at it, yet it makes a big difference.

Look at the bright side. You're SMART. You stopped and ASKED before proceeding. It could have been a lot worse.
Click to expand...


Yes. A small shim will make a big difference.

A big shim will put you off the map....


And it is a good thing that he stopped and asked. Now he has learned, and we can get him straightened out where he will be able to do this himself.


I have the pictures downloaded from my camera, now I have to label, reformat, and make a thread on how to. He's gone for now, I'll post a link in this thread when I'm done....
 
A shim is not a nut. If you want a little more pressure use a washer about .020" thick. It takes very little to get a lot - as you have noticed.
 
krazykuda said:
Thanks Rob. :D
Click to expand...

these two last posters,rrr an kraz are spot on. I used to shim the springs on chevys to adjust the pressure, it don`t take much! I bought an adjustable pressure set up from mancini (I think), didn`t need it, still in the package if anyone needs one. pretty cool little deal-------bob
 
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