Hello everyone. I have a 78 F100 4wd and i have some issues with my power steering and hydroboost. Recently I seem to of lost power to my brakes and the steering has become "lumpy" ie it turns smoothly for an eighth of a turn then binds up then turns smoothly again.

Now the pump and the hydroboost are both fairly "new" reconditioned Cardone items but i am starting to wonder if something has let go in the steering box and fluid is just blowing through the hydroboost and power steering box without pressurising up.

Also as i am in Australia it is right hand drive. It looks like someone has welded a plate to the chassis and bolted this power steering pump on. It is a ford one but im not sure if its the original.

I have tried bleeding it while on a jack and turning the wheels side to side but no good.

Am I on the right track suspecting the power steering box?
Can anyone ID what type of box it is?

Thanks for your help.

 

Bump.

I wish I could answer your question but I cant; that steering box looks like a gamble the way it's mounted, though.

Maybe you can pull those cast numbers I can see part of and run them through Google to figure out what it is.

Have you considered putting a stock steering box back on?

What are the pump and booster off of?

 

looks like instead of doing a steering column link to the gear box to compensate for a body lift,they raised the steering box....kinda lame if you ask me.

 

A user of fullsizebronco.com reckons it's a box off a 73-79 2wd lhd truck, which would explain the non standard mounting. The rhd 4wd steering box is an Australian only item, and people want crack pipe money for them, so i''ll be sticking with this box. Or at least this style of box.

 

I agree with the 2wd steering box and would swap the pump first.

Some of those rebuilds are...well....rebuilds. My first did not last a year.

 

What power steering pump are you using? I had my expensive benchworks saginaw pump crap out in a day, replaced it with a found saginaw pump (could have been a Vega pump) and was experiencing what you have, swapped it out for a blazer pump (with hydroboost) and now it steers like a dream...

 

Its a reco saginaw pump. Its even got a chrome cap!

 

There was a note with my replacement pump that stated "On Hydroboost applications: If unable to obtain sufficient system pressure, transfer the valve from the old pump to the new pump"

I didn't have a valve from an old pump, but when I replaced my pump no more issues

Anyone know what the correct pressure should be for the hydoboost system?

 

Well i took the "reco" pump to the local shop and they said it was down in pressure. Only 800psi max rather than 1000+. Apparantly the inside of the pump had been machined so the clearance was too big. This was fixed and the pump is back on the truck. The brakes are better, but still not good. And the steering is still "lumpy". Maybe I have a steering box issue too?

 

Well, if you wanted to really eliminate the pump, you could swap it out with a junk yard unit. They are pretty much the same, even if the reservoir is different, as long as you stick with a Saginaw pump. You can even switch reservoirs on yours if that makes it easier.

There are even people who change a few things with the pressure ports, which you can buy online, to vary their flow for what they need.

If you go tinkering with the port, though, be careful; there are at least two different thread types out there. Make sure you get the right one, metric or SAE, for your hoses.

Here is some troubleshooting that you may be able to try.

I have no clue about the lumpy feeling steering, but I'm about certain that no one will be able to help you if they dont know what the pump and hydroboost unit came off of.

Maybe they are grossly mismatched?

Have you tried removing either the steering box or the booster from the hydraulic circuit to see if anything changed?

 

the 1978/1978 ford steering boxes have the lines (pressure and return) conected to the underside of the box. Your photo clearly shows the lines on the top so no only is your box mounted badly but it's not stock.

 

It's a 2wd box mounted on a right hand drive 78 4wd.