Oil Pressure/Braking- 95 Yukon 4x4

[GalDemSuga]

Folks

The oil pressure guage goes to "0" whenever I brake hard.
Originally the truck kept blowning off the oil cooler return line at the oil filter adapter, so I have disconnected that until I can fab a better connection besides those flimzy GM quick connects. Then I started noticing the pressure going to 0. It returns to about 35 psi when I let off the brake. Is this a cause for concern?

 

[nvrenuf]

Electrical or mechanical gauge? Factory or aftermarket?

Will it do this sitting still or only moving?

 

[Fordum]

Well, it would bother me.......

This is a classic example of what is the real problem?
Is the pressure going to zero, or is it the gauge going to zero?

Of course, I'm assuming that its a factory electric gauge.

If we trust the gauge, then you are either real low on oil, there is a baffle gone in the pan, ( not sure there is one) or the pickup tube has come loose or is screwed up some way on the pump.

Or else you are just braking too darn hard........

Check the oil level, probably already have, and try to determine if the gauge is right.
If its electric, I would suspect the wire on the sending unit being broken or loose.

When you disconnected the cooler line, what did you do about the hole?
Most aftermarket adapters have all the oil go through the cooler, possibly with a bypass for a clogged line.
Not sure how the factory one works.
So, if you plugged it, you have got a problem. That oil needs to go somewhere.

Either way, if it really is the pressure, you need to find out the problem.

Odds are its the pickup tube on the pump, and it can fall completely off with dire consequences.

 

[GalDemSuga]

factory electrical gauge and only when moving.

Electrical or mechanical gauge? Factory or aftermarket?

Will it do this sitting still or only moving?

 

[GalDemSuga]

The lines ports at the adapter are plugged now. I've also ran an adapter that didnt account for cooler lines and the gauge still goes to 0 when I brake, otherwise it runs good.

Well, it would bother me.......

This is a classic example of what is the real problem?
Is the pressure going to zero, or is it the gauge going to zero?

Of course, I'm assuming that its a factory electric gauge.

If we trust the gauge, then you are either real low on oil, there is a baffle gone in the pan, ( not sure there is one) or the pickup tube has come loose or is screwed up some way on the pump.

Or else you are just braking too darn hard........

Check the oil level, probably already have, and try to determine if the gauge is right.
If its electric, I would suspect the wire on the sending unit being broken or loose.

When you disconnected the cooler line, what did you do about the hole?
Most aftermarket adapters have all the oil go through the cooler, possibly with a bypass for a clogged line.
Not sure how the factory one works.
So, if you plugged it, you have got a problem. That oil needs to go somewhere.

Either way, if it really is the pressure, you need to find out the problem.

Odds are its the pickup tube on the pump, and it can fall completely off with dire consequences.

 

[Fordum]

factory electrical gauge and only when moving.

In that case, check the wiring of the sender.
Might be hard to do with crossed fingers on both hands, but hopefully its a bad connection.
Hope for the best.

Also, if the sender doesn't seem to be the problem, try shaking the harness under the dash with the engine running.
It might be moving when braking and causing the problem.

 

[79rustyk10]

Ive never seen a SBC oil pan without the baffle, not to say it couldnt have been removed or god only knows what.

Sounds like really low oil almost.

 

[DokWatson]

I would drop the pan and make sure the pickup tube is still attached sooner than later. When you brake the oil is sloshing away from the pump and will eventually be the cause of failure

 

[Chevy305]

Check your oil!!!

 

[Fordum]

Ive never seen a SBC oil pan without the baffle, not to say it couldnt have been removed or god only knows what.

I figured if it was missing, it had popped loose and was laying in the bottom of the pan. Not sure how it is attached or how big it is.
I was thinking spot welds.

But, I suppose it could be simple theft.........Seen anyone suspicious hanging around lately???

I wonder what the black market price is for a SBC oil pan baffle..........