Is it common for SBC oil pump pick up tubes to fall off?

So I am working on another Chevy that is a customer car with a 307 in it. 83,000 original miles. Hasn't been driven much in the last 3 years. daily driver before that. I was commissioned to get it back on the road. ( new starter, battery, etc.)

I noticed while out on a road test that when you slam on the brakes or down a steep hill that the oil pressure light comes on and the pressure gauge drops momentarily. Otherwise at idle in the shop it has 25psi and almost 50 at cruise on flat terrain. First, yes it has the correct amount of oil in it.... Obviously bearings are a concern, but the fact that it has good pressure other times makes me believe it's not that. I've also thought it could be plugged drain back holes. I've been doing some reading online and it seems that it is fairly common for the pickup tube to fall out? would these cause symptoms like I described. I've heard of guys dumping another quart in and if the problem goes away it's a pickup tube....Is this correct? The customer states it didn't do it before it sat for 3 years. any other test before I pull the pan and measure bearing clearances? Just looking for a little brainstorming before I tell them "runs good, needs motor"

Thanks

 

Not common, but yes, happens, most old books on rebuilding tell you to braze the pick up on.....I have done 100's and it only happened 1 time, and I learned my lesson....and a paying customers car to boot!

 

Yes. Very common. A couple of TIG welds between the tube and housing usually fixes it.

(Or brazing as mentioned above)

 

Not just Chevy but Pontiacs and others too. I had one fall off on a 389 Pontiac and without the screen in place it sucked up a piece of the plastic timing gear and locked up the oil pump. Mine would also lose oil pressure when braking as the oil washed away from the open hole in the pump.

When you put the new one on braze or weld it in place so it will never happen again.

Don

 

well they told ya right. its not common but does happen some.ive never had it happen to me but it did to a freind of mine.ive only seen it 2 times but heard of it more.now we braze them all so i wont happen to me.

 

ive only done a few, a pontiac and chevys, and they were very hard to get in. it took a long time to get the tube in so forget about it falling out. im not saying its imposible but it seems very unlikly to me.

 

4X, also learned the hard way........
New pump, new pickup......install with no pan gasket...make sure pickup hits the pan, take off pan, weld (TIG) pickup to housing...reinstall pan with gasket.....every time.....

 

I always spot 'em on with a mig tac weld

 

have seen them fall out on a few occasions--spot weld them to prevent this

 

If you decide to weld or braze the pickup first remove the relief spring. If left in could lose tension from the heat. I weld a strap to the pickup tube and drill a hole and bolt it to the pump body. That way the pickup can be removed from the pump.

 

insurance... Not every one came loose but it happened often enough that a quality HP engine always got the tube brazed in place before it was bolted to the block prior to everyone having MIG welders. Yes be sure to remove the spring before you do. A garden variety rebuild maybe not.

 

As most have said- yes,they will come out. A tack weld will do it.

Went for a ride in a 66 chevelle once....6500 rpm blast and my buddy shut's her down. I ask what's up? He say's no oil pressure......
Ok- I didn't hear any death noises,so i'm a lil puzzled.
He tell's my the pick-up has come out of the oil pump.
How the hell would you know that? I ask.....

Reply was "that it did it before"

Dumbass! 100 degree day and a 5mile walk home.......He heard about it the whole way home!

Tack the pick-up!

 

Common enough that it should always be tack welded.

 

Hitch, those pick-up tubes are meant to be used once and once only.

The gizmo in the pic is a excellent alternative to welding. Be sure to Loc-Tite.

Yes it is strongly recommended to use one of the 2 methods for securing the p/u.

3/8" of an inch from bottom of pick-up screen to pan, TR

 

So from my description it sounds like a pickup tube to you guys? It's got 25 psi Sitting here right now. Will get up to 40-50 on the freeway then drop when you jam on the brakes....and it doesn't make any death noises....I'm thinking when I drain the oil I can whack the bottom of the pan with my hand and I should hear something in there. The engine has never been apart so hopefully it didn't hurt anything.

 

Yes …. My boss’s fell out a few months ago.
Luckily it was a saturday and I was at home

 

No it doesn't to me. It's not an intermittent problem. It won't reinsert itself. Once it falls out you lose all oil pressure until it is put back in by a human being.

 

Either way I'm thinking I might drop the pan, If the pickup is laying there I found my problem, if not I can check the main bearing clearances.

 

that's what I was looking for and kinda what I thought....so it's probably bad bearings. or? sticking pressure relief

 

It sounds to me like it's low on oil or the oil is sloshing around. Bad bearing don't care if the brakes are applied or not. Double check the oil level. My first car started to do that when I was a young dumb ass buck. It was just low on oil.

 

From this description the pickup may not be the culprit but the oil pan is. The stock SBC oil pans have a flat plate that ran from the front of the pan back and where it ended there is a piece of sheet metal mounted on the bottom of the pan that extends up to close off the flat plate. This "baffle" keeps the oil in the oil pump area during deceleration. I used to see aftermarket pans without this feature and the situation you have would occur every time.

 

Oil level was the first thing I checked. It's full.

 

Pump is partially submerged in oil. So there will be oil pressure at idle and anytime the inlet hole is covered. Not at high speed, braking or turning.

I have seen a few pickup screens laying in the pan.

Had one fall off on a 69 Chevy hardtop back in the day.. Went to pass another car on I-75 and the motor went CLICK! The warning lights all came on and I coasted to a stop.. Later inspection of engine and had to cut the rods to get the crank out.. Welded up solid.

 

X2 I do this everytime!

 

I use an 1/8" dowel pin to lock them in place...

 

My question did you ever see a factory installed one fall out?

 

Nope!....

 

YES, the incedent in previous post was a four year old original car..

 

So what would make a SBC lose oil pressure going downhill and on hard braking?

 

Sounds more like clogged pickup screen,no baffle in oil pan or wrong dipstick giving you a wrong reading. If the tube falls out you ain't going to get no 50lbs oil pressure anytime.