Not sure where the best place to post this. I have a 2000 7.3L with 260k miles that I bought new. It has gone through 8 pump to hydroboost lines in 2 months. The factory line lasted 13 years. The replacement lasted 5. The last several have failed within 2 weeks, the shortest time was 24 hours.

Every time the line has failed at the fitting to the pump. Whatever is holding the flare inside the nut gives way, the flare slips back and all of the fluid dumps through the nut.

No one can give me any answer but I have developed a theory over the past couple of days. Wondering if it could be a check valve in the hydroboost that is allowing a pulse back down the line to the pump overpressuring that fitting. I've found mention of a check valve for backup pressure accumulation but can't find a hint as to where it is or how to check or repair anything.

I'm getting good at replacing hoses but I would rather not have to keep doing that every week or so.

 

Keith,

Did you find a solution? Just blew a brand new line with new pump and not wanting to do more of them.

Thanks!

 

Is it pulling out and stripping threads? If so the threads in the pump are probably damaged and it will happen again. Is it possible your lines have metric threads and the pump is SAE?

 

No, not stripping threads. The Ford proprietary connector isn't a true pressure fitting with metal backing the connection. Inside that nut is just, I assume, some sort of polymer or a friction connection. The line slips back 1/16 to 1/8" and the fluid blows out around the line.

I did fix it. I bought one of these, Russell 648030 (6 AN) Power... . Had to modify it by cutting the ridge inside the o-ring back and used a drill to open up the connector on the pump slightly so that the o-ring would go in and compress tight. Took one of the bad lines to a hydraulic shop and had them cut, flare and install the proper connector. (Didn't want to spend the $100+ to buy a 37° flaring tool I would hopefully use just once. You might have to do that, though, as a lot of shops won't work on power steering lines or anything not made by them.)

Put that all together over 6 months ago and haven't had a problem since.

 

Keith thank you. So did you also do your hydro boost? (And eliminating any over pressure / relief valve issues?) Or just the custom hydraulic line fixed it?

 

I previously replaced the hydroboost with a Cardone rebuild. And replaced the pump with a rebuild. Only things in the system not replaced were return lines (no hint of blockage there), hydroboost to steering line and steering gear. Was going to replace the steering gear but never did figure out the number of splines to get the right one. Replacing that connector was a lot cheaper and easier so just did that first.

 

Hmm, but you still blew lines with alarming frequency after your reman hydro boost and reman pump were installed? Or you did it all / some at the same time? (Your custom hydro line / pump mod) You see what I'm getting at here...

Today I put on my old hose with new Teflon and I have power steering for the first time ever in that truck... the motorcraft new hose blew in 90 seconds... still trying to figure that one out.

 

Yep. Lines kept blowing after replacing pump and hydroboost. Never did figure out the cause. It's my only vehicle and I work as a handyman, always way behind on my work with no time to take a few days letting the truck set idle while I figure it out. Just carried a spare with me at all times and swapped them out when they failed. Didn't go as quickly as yours, usually lasted a few days. Thank AutoZone for warranties.

 

Appreciate the response. Interesting stuff. It was likely this mysterious relief valve on the PS pump or HB you replaced. Maybe slightly out of spec leading to occasional overpressure situations.

Glad you got a solution - I'm shocked no one sells a better aftermarket hose for this with flared fittings. Seems like people sell everything for these trucks.

I've got a spare motorcraft hose on hand, but I'm thinking I'll wait until the stock ones blows... I hate that feeling though.

 

$150 Motorcraft hose looked more substantial but didn't last any better than the $30 ones from AutoZone.

Pretty sure you're right it's a momentary pulse from somewhere. But no one can tell me what might cause it. And, obviously, a properly designed hose could handle such.

You seem to be the only person other than me to experience this, however.

 

My local hydraulic guys said if I had the truck maybe they could redo all the fittings. As cool and bulletproof as it might be, this sounded like lots of time, money, and non-standard fittings in my truck. Again, shocked that nobody makes this - hint hint Riff Raff product development. I'm keeping the old hose on the truck right now out of morbid curiosity, and having another Motorcraft hose on hand, with enough ATF to refill the system. I'll likely swap it in, replace the Teflon on the old hose, and keep it as a road spare.

 

I recently blew out the line aswell, and a year ago I replaced the power steering pump and all the hydraulic lines with Napa products. What prompted this was a whining noise during steering and breaking, and after getting stuck in deep clay I may have stressed the pump (steering in deep mud trying to get unstuck) oversteering and could hear the pump really struggling. and pressure built up that it blew the cap off the pump. The whining noise has been an ongoing issue since I bought the truck in 2020. It has always been hard to steer unless the truck was in motion. I thought it was because of the 35" tires, but I new something wasn't right.
After replacement of parts and bleeding pump of air in hydraulic lines (truck on jacks and steering back and forth for 30 cycles) note: the whining was still present so it wasn't the pump causing the whining. I did some research and found info and a schematic on how the hydrobooster works. There is an internal check valve in the booster that regulates where the pressure is needed as you steer and/or apply the brakes; and yes as one of you had stated earlier, it does cause a high pressure situation. So now after loosing that "Or" ring (stupid design) why I ask did Ford go with this design instead of the traditional flare design. I had a 1996 7.3 Ford that did the same thing. But also had a 2000 F350 with 250 K miles that it never happened (got lucky I guess). Note: I don't recall the 1996 having a whining issue just one day the hose pooped out.
So going back to my 2002; now i have this failed retaining "O" ring floating around either in the pump or the gear box (probably just sitting in the pump). When it blew the tubing out I imagine that there wasn't enough pressure to allow it to travel to the gear box. However I think at this time a major overhaul is in the forecast on replacing the Gearbox as the truck has 280k miles and alot of play (6" of steering play), a new pump and and a rebuilt hydrobooster.