The steering rack of my Volvo 780 leaks at the line that feeds the rack from the pump at the psg side, see photos. I tried to tie it but it keeps on spinning when it comes to the end, it won't lock.

I loosened it up entirely to see what's going on and to clean the treads. At the top there is a small O ring that I will replace. Besides the O ring can I use something like Permatex High Temperature Thread Sealant with a fitting like this? Or any other suggestions to make it from leaking?

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1979 Black on Black, 300CD (sold), 1990 Black 300SE, Silver 1989 Volvo 780, 1988 300CE (vanished by the hands of a girlfriend), 1992 300CE (Rescue).

From what I see you're S.O.L. The o-ring is what seals the pressure but without threads to hold the fitting you're fighting a loosing battle. The pressure in that line I'm sure exerts a very significant (estimated 500 lbs) outward pressure that I'd wager no patch could hold.

Plan to swap the rack and save yourself the grief of fighting it and losing.

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90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

Theoretically you could put a sleeve on the screw and re cut the rack side interface to fit the new sleeve diameter. You may be able to use some type of epoxy or quick dry urethane on the rack side interface and then let the screw threads re-tap the freshly made surface. I have no idea how long this would last but some urethanes are very strong.

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Toyota is a leader only because their drivers block everyone behind them. Oh what a feeling.

I'd at least try a new hose to see if it is the threads on the pipe side that are stripped, although they don't look bad in the photo which suggests it is the rack which is stripped.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Helicoil?

In the worst case before getting a new rack I could use JB weld or silicone and see if that works. The rack is a rebuild one, installed it little over a year ago...

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1979 Black on Black, 300CD (sold), 1990 Black 300SE, Silver 1989 Volvo 780, 1988 300CE (vanished by the hands of a girlfriend), 1992 300CE (Rescue).

I would try something stronger than either. Silicone is way too soft to stand up to pressure. I don’t know enough about JB weld, but have only heard good things. You may want to contact a local supplier of plastic resins and see what they recommend. Fiberlay is one supplier with awesome support. Some of urethane compounds have a high volume of aluminum. It is not expensive in small quantities.

Were it me, I’d try some quick dry urethane first and if that didn’t work, I’d use a sleeve and re-cut the rack side to fit. As another and probably better alternative, you could widen the hole on the rack side and cut in a sleeve that matches the existing screw side. If that failed go for a replacement rack.

If you go the route of applying a resin, clean everything really well with lighter fluid (my favorite cleaner) and paper towels. Use lots of ventilation and a fan while cleaning.

As another alternative, you could pull the rack and take it to a machine shop. A competent shop could rebuild the threads so it would be stronger than new. That would still be a lot less $$ than replacing the rack. Unless it is showing other problems…

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Toyota is a leader only because their drivers block everyone behind them. Oh what a feeling.

I may be looking at this wrong, but....

From what I can see the leak is at the point where the pipe comes out of the 'nut'. If this is the location of the leak then there is nothing to do but replace the hose since the pipe is cracked or bent.

The O-ring seals inside the orifice and the pressure goes through the pipe. If the leak is coming out where the 'nut' screws into the rack, at the threads, right up next to the rack, then the 0-ring is not holding and needs to be replaced.

If the oil is leaking from the back of the 'nut' where the pipe goes into the retaining nut there is a crack in the pipe itself where the 'nut' has rubbed a hole in it.

These have to be installed dead on center and there is no room for error. I like to line them all up, screw them in finger tight if possible (making sure they turn freely) and then mount the rack and pinion to the body or other mounting points. Then it is just a matter of a final turn or two with a wrench.

Another vote for this.

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-Justin

91 560 SEC AMG - other dogs dd
01 Honda S2000 - dogs dd
07 MB ML320 CDI - dd
16 Lexus IS250 - wifes dd

it's automatic.

It seems to be the most solid solution, but I don't see how I can do this without getting metal parts into the rack?

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1979 Black on Black, 300CD (sold), 1990 Black 300SE, Silver 1989 Volvo 780, 1988 300CE (vanished by the hands of a girlfriend), 1992 300CE (Rescue).

You could keep a vacuum on the area while running the drill and tap. That would get most filings.

But…

A heli-coil fix may leak when under pressure, unless a suitable crush washer is used. There are many reports of this problem.

That's why i suggested a sleeve. It amounts to the same work to drill and tap but employs a solid insert.

edit: "Timeserts" seems to be a preferred solution for high pressure fittings.

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Toyota is a leader only because their drivers block everyone behind them. Oh what a feeling.

It looks like it that when they did the rebuild of the rack, the rebuilder did a heli-coil. I was already suspicious that something was off, when I unscrewed it the first time round silver metal slivers came out.

I'm heading to the JY and see if I can find a rack on a low mileage car and then I can slowly rebuild this one properly. I need the car up and running again.

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1979 Black on Black, 300CD (sold), 1990 Black 300SE, Silver 1989 Volvo 780, 1988 300CE (vanished by the hands of a girlfriend), 1992 300CE (Rescue).

Can you return the rack to at least get your money back?

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

Well, I read it wrong the first time.

If there are metal slivers coming out when you unscrew it then something has failed. And it will never be right again.

But.....

Is it possible to buy a fitting that your current hose will screw into and seal up in that has threads that will fit into the existing hole? If so you could screw this fitting in and epoxy it in with some JB Weld and then attach your existing hose fitting into the 'new' fitting that is now sealed in by the threads that are left and the epoxy?

I am thinking of some sort of adapter but with a very specific use. A hydraulic supply house might be able to come up with something and it would be easier to screw this new fitting in that to replace the rack.

And if the threads on your hose are good you would not even need a reducer. A one to one would work. Just make sure it is made of steel and not brass.

Ebay has reman units for a 780 for $300 and change or less. Some include free shipping...

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Toyota is a leader only because their drivers block everyone behind them. Oh what a feeling.