Fuel Pressure And Hydraulic Buzzing?

[Kotta390]

It has been awhile since I posted about my cracked 55 block. I have that band-aided for now and it mostly holding up.

 

 

I have however been experiencing some strange phenomenon with my fuel pressure. When It is cold outside <35F, my fuel pressure is around 15.5-16.5psi at idle and when I drive the truck a good ways, it will creep up to around 17-18 at idle which is fine. The other end of the spectrum is when it is warm outside. >75F, the fuel pressure will be around 18.5-20psi at idle but never really goes above that. I have the AD150 and full big line kit along with a needle valve. Sometimes the fuel pressure fluctuates a little but it is slow and the gauge doesn't go crazy, it is a very clear and slow movement. Any ideas?

 

 

 

Second issue is when it is less than <35F, the hydraulics or what sounds like my power steering and braking system has a loud buzzing noise when first cranked up and the warmer the weather gets or the harder i drive it in the cold, the buzzing goes away and I never notice it anymore. The breaks and power steering are not affected by any means but it is loud on cold mornings. What is going on here?

 

 

Thanks for all of your help.

[JAG1]

I have the same exact thing going on with my fuel pressures. I assum it is normal ambient temperatures affecting the thickness or liquidity of the fuel. Mine's been that way always.

 

As for the hydralic buzzing..... I had the same exact thing happening there too. After reading of a guy with the same problem, stating he changed out the power steering fluid with synthetic fluid and the noise went away, also had smoother steering.

 

I did as he recommended, robbed my wifes turkey baster, Kept sucking out the old fluid, putting in new synth several times till it basically got changed over. I would change as much as I could then drive it causing it to mix with the old and change it again till it was perfectly clear.

 

I have never had a problem since and it helped the old first gen truck also.

 

Please do go out and buy your wife a new turkey baster before she finds out though....... it's the worst thing in the world to get in trouble with a nice lady on Thanksgiving day. :banghead: :banghead: :banghead:

 

Don't just try cleaning it and putting it back neither

 

Use Valvoline Syn Power

Edited February 26, 2014 by JAG1

[diesel4life]

It could simply be the grid heaters drawing enough amps from the battery that it is keeping your fuel pressure down a little until the truck warms up. Next time it is cold watch the voltmeter to see if there is a correlation between grid heaters running and lower fuel pressure. That is completely normal.

Does your power steering system have any leaks? When the pump is cold and the fluid viscosity is thicker the pump can possibly suck air if there are any leaks on the return side or even any from any leaking seals in the pump itself. Check the fluid in the resevoir after the truck has been running, does it look foamy? It sounds like your describing a caviting pump so check for any leaks, and if the fluid looks dark/burnt it would be a good idea to flush the system. Check out the write up on this forum it is a pretty good one. PS fluid and brake fluid seem to be the two most overlooked fluids to be included in a maintenance program but they are both very important.

How did you stop your block from leaking?

[Ilikeoldfords]

My PS system gets real noisy in the cold too. Just like any other fluid it is just cold and doesnt flow that well in the cold. I am looking to change out all my fluids to synthetic eventually just to help everything flow better in the cold. It is really nice to have almost instant oil pressure on the mechanical gauge when its -30 outside.

[rancherman]

I had an old engineer (my Dad) ream me out years ago for thinking 'cold fluids' should make more pressure! ( I used to think thicker fluid would 'stack up' and effectively make more pressure) Dad had a funny way of teaching his young! LOL What it boils down to is thicker fluids take more energy to travel along a path.. or pipe. Friction really takes it out. Add in the added resistance from the filter, and screens.. PLUS the resistance in the intake side of the system to boot. (No pump is worth a dang if itself can't be fed as much as it puts out) I would love to have your numbers! as far as the buzzing ps, mine too does it, when it's very cold. Warm, it's fine. I think it's just too thick for the system, and some of it's getting bypassed @ the pump. I've noticed that when it's a tad 'low'... it'll do it more readily when cold. Makes me think it's possibly cavitating (low level, and thicker ps fluid makes it easier to pull air from top of reservoir).

[Kotta390]

No leaks and also heater grid has been disconnected. I can change the fluid if that will help but the fuel pressure thing is mind blowing.

[KATOOM]

The power steering and brakes work wonders better when using a good quality full synthetic PS fluid.  Not to mention PS fluid is the most neglected fluid in a vehicle next to brake fluid.  Plus these hydrostatic systems build a lot of heat which will degrade regular PS fluid and cause growning noises and poor steering/brake performance over time.  This problem is exagerated even more in the cold climates.  Get a quart of full synthetic PS fluid and change out the resevoir twice to get all the old crud out and you'll notice a difference.

 

And I notice my fuel pressures doing the same.  Cold weather will cause higher fuel pressures and hot weather will cause lower fuel pressures.  But.....not right away.  When I first start up in the winter the FP is lower and then will rise to a high when everything is warmed up, but when in the summer when I start up the FP is higher and will drop to a lesser pressure when everythings warmed up.

[Kotta390]

Edit* Double Post

Edited March 7, 2014 by Kotta390

[Kotta390]

I notice the same thing with my fuel pressures!! That's weird they do that but it makes me feel better that I am not the only one with this issue. As long as it stays above a constant 14psi, I'm

Ok.

As far as the power steering fluid, what kind should I get? I have no problems with steering but sometimes my brakes are extremely touchy in the morning or until I get some heat into the brakes...they tend to lock up quickly but after a little driving all seems well.

Edited March 7, 2014 by Kotta390

[Ilikeoldfords]

As far as the power steering fluid, what kind should I get? I have no problems with steering but sometimes my brakes are extremely touchy in the morning or until I get some heat into the brakes...they tend to lock up quickly but after a little driving all seems well.

 

Amsoil makes a good full synthetic power steering fluid. As for the brake issue, I would be checking your pads/shoes. Usually if they are getting thin, it will cause them to be kind of grabby until they warm up. Had it happen lots of times to different vehicles.

[KATOOM]

I notice the same thing with my fuel pressures!! That's weird they do that but it makes me feel better that I am not the only one with this issue. As long as it stays above a constant 14psi, I'm

Ok.

As far as the power steering fluid, what kind should I get? I have no problems with steering but sometimes my brakes are extremely touchy in the morning or until I get some heat into the brakes...they tend to lock up quickly but after a little driving all seems well.

 

I believe there are a few different fully synthetic PS fluids out there.  I happen to run across a quart of Redline when I did mine.  And a quart was the perfect amount to allow one flush and then a refill.

 

As for the brakes, do you have rear drums?  If so its completely common for them to be grabby first thing when the weather has any amount of moisture.  After a couple taps of the pedal they calm right down.

[diesel4life]

Drive any Chevy or Dodge with rear drums, when they are cold and wet they will grab like no tomorrow. Mine will actually lock up if I stab them to hard before they get a little heat in them.

Off subject, but please induldge on your temporary fix for your cracked block! Did you smear some epoxy or jb weld?

[Kotta390]

Currently I am running a BG stop leak. It has slowed the leak down from 1.25 gallons a day to a half a gallon a week! It's temporary I know but for the mean time I just don't have the funds to even consider a block or engine swap.

[dripley]

Currently I am running a BG stop leak. It has slowed the leak down from 1.25 gallons a day to a half a gallon a week! It's temporary I know but for the mean time I just don't have the funds to even consider a block or engine swap.

 

 

??????

[Ilikeoldfords]

??????

He's got a cracked block. Dont know if you saw it but I think he was talking about it in a different thread.

[diesel4life]

Currently I am running a BG stop leak. It has slowed the leak down from 1.25 gallons a day to a half a gallon a week! It's temporary I know but for the mean time I just don't have the funds to even consider a block or engine swap.

Have you looked at the Lock N Stitch website? If your crack is small enough to be stopped up by bars leak I would definitely give them a try. It is not a gaurantee but has been a successful fix for alot of engines. It is inexpensive compared to the alternative, the most you would be out is your time. Remove everything in the engine compartment that is in the way, and follow the directions to the tee and I bet it would hold up for a long time.

[Kotta390]

Have you looked at the Lock N Stitch website? If your crack is small enough to be stopped up by bars leak I would definitely give them a try. It is not a gaurantee but has been a successful fix for alot of engines. It is inexpensive compared to the alternative, the most you would be out is your time. Remove everything in the engine compartment that is in the way, and follow the directions to the tee and I bet it would hold up for a long time.

I will look into this. The only things I need to remove are the battery, turbo, intake and downpipe for the most part.

[mulcher812]

Are you running a mechanical fuel pressure gauge? If so do you have a snubber inline with it? if your running a snubber try opening the snubber or closing it about a half turn. I was having the same issue with my ashcroft mechanical gauge and found that the fuel pressure going through the snubber was creating a buzzing of harmonics in the line and inside my truck.

[Kotta390]

Mechanical and I'm running a needle valve. Now that it is warming up it is a rock solid 18psi and doesn't fluctuate at all. The buzzing was not fuel I can promise you. I could feel it in the steering and the brakes I thought lol.