Hey everyone, I wanted to show a simple trick I learned a long time ago in a carburetor shop.

The issue in question is the typical "moist/leak" around the rack's adjuster bolt. Almost EVERY rack and pinion uses this type of design to adjust the preload of the rack shaft so it is in specifications. This bolt is responsible to keep that shaft centered which keeps your pinion from destroying itself as well as outside seals. The two-part design is one that is a bit controversial since it will "always" try to leak vs the Capped design.

This adjustment screw is responsible for shaft play, unfortunately adjustment on older units most times leads to failure due to the wear on other parts as well. The half moon, the shaft and the plastic bushing that the rod rides on will all wear so as you adjust you put additional strain on the rest and you'll kill the rack faster.

Now for the leak.



If you pay attention to this design, you'll notice what I mean. There is no sort of O-ring or washer that will prevent the seeping through the thread. As folks go through their powersteering system and try different fluids in the rack's life time certain fluids will mix with others and decrease the thickness of the fluid causing it to leak more and more.

The fix: Paint

This trick is used on throttle blades as well (different material) as well as in the plumbing world where you need threads to act as seals. The issue is many folks have tried the removal method which most end in failures due to the rack start to leak all of the fluid as well as the inability to replace the preload you just removed.

Steps:
1. Get some carb/brake cleaner and blast this area really well.
2. Use some sort of compressed air/ heat gun/ hair drier to dry this area as quick as you possibly can. Repeat step one until you can truly determine that it's clean.
3. Use some paper towel to purposely cover this bolt/nut aiming for the threads. The paper towel will absorb any remnants of powersteering/carb cleaner stuck in the threads and can show you when the threads are cleaned and dry
4. Confirm 100% that the entire area is cleaned.
5. With some Rustoleum Enamel paint either in a spray bottle or with a stencil go to town on this bolt. Seriously, glob as much as you possibly can concentrating on the threads as the pictures show.
6. The idea is to have the paint penetrate into the threads and build a layer that will act as a seal (similar to copper gasket spray)
7. Help the process out by heat or air so the paint can dry faster. (needs to overcome the rate or the seep from the rack or else the paint will never dry)

If done correctly it should look like the pictures below. I did this process 3 years ago on my rack replacement. I ended up with a used unit that had this leak and this process worked.
Why do this? To prevent getting upsold a whole new rack over this silly leak, to prevent this leak from destroying the driver's side boot and overall decrease any sort of power steering fluid disappearance.
This is a common issue that many have suffered from and many dont have an idea on how to tackle it.

 

So the rack adjuster bolt manages the preload on the rack gear causing it to mesh tighter with the pinion gear correct? This should not be adjusted once in place as it will put additional strain on other aged components within the rack, causing premature failure.

Since the fluid leaks/seeps at such a low rate on most of our cars, is this fix required, or is it only recommended for a leaky rack to avoid replacement of the expensive rack assembly? If the latter, once you drain the PS fluid and reinstall the rack adjuster bolt with the required paint, then how do you know how tight to adjust the bolt to get it within spec (torque?) and not cause additional damage to the other aged rack components? Are there advantages to applying the fix on a rack with the standard seepage (below) and bringing the preload back into spec? Would something like teflon thread tape work as well?

 

So this is meant to avoid being upsold a new rack as well as to decrease this moistness from affecting the driver's side boot.

You dont need to remove the screw/nut combo just clean it really well and glob paint. This paint will act as a seal using the left over threads and the nut as the new surface to hold the paint onto.

As far as the setting of the preload I suggest against it with a used rack. Remember that this adjuster will push/pull on the rod. Your outer rack bushings have worn down to the set pre-load it has so adjusting it could possibly create a leak as well as tighten the steering a bit more than what you would want.

 

Thanks. This looks like a good proactive project to tackle the next time I’m under the car changing oil.

 

I agree. In your case you're no longer moist, you have started to leak

Make sure you do this with the car cool. In your case it might be a bit harder to get it to not drip oil as you're cleaning it. Clean it with white paper towels being that they will show you were there's extra oil.

Needs to be a dry as possible for the paint to stick and then it needs to sit and dry for a bit. I usually leave enamel paint over 10 hrs to dry.

 

I've never seen a drop of fluid on the garage floor? I had the classic moist look a few weeks back, but I tried to reach up under the car and wipe it from afar as I wanted to see how long it would take for the moist look to return. I probably need to check it out again when I'm under there as the photo may be misleading.

I have a trip up north planned Wednesday, so I cleaned it up a little better this afternoon, then look for leaks when I return wednesday. If you look closely, it almost looks like paint or something similar was added to the threads originally?

 

Love this! Is there a reason to use paint and not thread sealant?

 

Not sure to be honest. I think it seems normal for a little hydraulic fluid to leak past the threads over time. Mine never showed any signs of leaking until I cleaned the area; it’s like the 9 years worth of accumulated dust and dirt served as a seal. Now I just wipe the small amount of residual fluid off during each oil change (5-6 month intervals). The steering racks on these cars are part of the iconic heritage. Somewhat raw compared to the best electronic steering on today’s cars, but an excellent representation of the analog feedback many of us enthusiasts still prefer.

 

Simply, plaint is much thinner and faster drying. Sealant might not dry in the time it takes the rack to moisten this area up again which will then cause it to never harden.

The idea is to prep properly and use a type of fast trying sealing compound. Glues and silicone will not last as long as paint will.