Power Steering Reservoir Fittings leak

I don’t normally roam around the KW thread, but the company just bought in so I’m researching.... anyway enough about me, here’s what I know and what I can help with.

That is sometimes called a “boss” o-ring, SAE straight o-ring or another couple different slangs, but

1: you have the jam nut to tight on that fitting. And that is why the o-ring you installed failed. To repair. Remove the fitting, back off the nut all the way. There should be a washer that will move around “an area void of threads” (if it’s missing the washer you need a new fitting) put the correct size o-ring there, (the higher the heat rating the longer it will last) thread the fitting in until hand tight, then back it off until it points in the right direction. Tighten the jam nut, install your hose.

2: 90% of the time, when a hydraulic reservoir (including power steering) pressures up enough to “remove the cap” and blow all over, it’s because the system is sucking air. Normally it’s from a hardened suction line that needs replaced. You might be able to bandaid this by replacing the spring clamps with a screw clamp ( spend the dollar more for the ones that have the extra wrap for silicone hose). I usually replace those hoses with a generic nylon braided hose and it will last a few years until the truck has earned the expensive “built” hoses suggested before. You should be able to seal this up for under $20 depending on how generic of a hose you find. Just make sure it’s rated for petroleum.

And don’t use Teflon on these types of fittings. When the O-ring is installed correctly, it will last a long time.

 

Not trying to put you down, but welcome to dump trucking. I have worked at a fleet with dumps for over eleven years and work on quite a few on the side. Every owner is the same, get a quick fix and then it will be a winter project but they never want to spend money in the winter. They are labor intensive and require a lot of maintenance. It never ends. In my experience the push-on hose works fine on a tractor, but really doesn't hold up well on dump that gets a steering workout day in and day out. Nowadays, crimp on hoses are cheaper than the field reusable ones that used to be very popular. We used to fight P/S leaks on our trucks til we just converted the ones that could be converted to JIC ends. Some of the newer stuff has brazed on push-on ends on the reservoirs and coolers. Found they best hose was a push-on rubber hydraulic hose with the spring clamps. Once the hose gets hard, you might as well replace it. For o-rings, I use the ones out of my Cat o-ring kits. Very hard to beat Cat o-rings.

 

2nd the Cat O-rings. You should easily get a few thousand hours out of them before they start to harden up. Best practice is to replace the o-ring any time you disturb it.

 

I bet..... if you don’t remember the washer being on the fitting, it must have stuck with the O-ring to your reservoir / pump/ etc. I can see the washer exists from your pictures. So you may have threaded the fitting out of the washer and your plastic ring you replaced with rubber, might have been to reduce friction between the nut and the washer.

When you try again, make sure the washer comes off with the fitting along with the O-ring after that.

But this is just a spit ball Idea from 1000 miles away.....