Lucas Power Steering Stop Leak SUCCESS! - PeachParts Mercedes-Benz Forum

shertex · #1 08-06-2014, 07:14 AM

My only disappointment with the 98 E300 I picked up last fall was a leaking steering rack. The fluid would drop from the max mark to the min mark over the course of about 100 miles. Not gushing, but a problem nonetheless. A decent rebuilt rack runs in the $400-450 range, plus whatever the labor would be. Really didn't want to spend that kind of money.

So I thought I'd try some Lucas Power Steering Stop Leak. The effect has been pretty remarkable. I kept topping off the reservoir with the stop leak. Over the course of 1500 miles I used about 1/3 of a bottle (i.e. about 4 oz.). I noticed the leak was slowing dramatically...so then I started making careful measurements. Over the course of the last 550 miles the fluid is at 3/4 of the way between max and min marks. So, it looks like currently it would take about 2200 miles instead of 100 miles to lose the same amount of fluid.

So I will keep topping off until it stops completely. I have a long way to go before using the maximum amount of fluid that Lucas recommends: 2 bottles. Even if it doesn't stop completely it's certainly slowed enough that i won't be buying a rack.

I don't doubt that, at some point, I'll need to replace the rack. But that's a LONG ways away now.

DieselPaul · #2 08-06-2014, 08:14 AM

Someone is about to post that you've ruined your rack.

I used the stuff with success on my dads Lexus because the rack is incredibly involved. 3 years later its just now leaking again, so its probably rack time. But buying 3 years for under $10 was worth it to me.

Junkman · #3 08-06-2014, 09:56 AM

I would fix it at my convenience. I've seen people fix cars getting them ready to sell. I figure that I'd like the benefit of having it fixed - especially if I plan on keeping it.

eatont9999 · #4 08-06-2014, 01:41 PM

It's true you are just buying time but racks are sort of a consumable item since most of them can't be rebuilt. It's not like you are going to hurt it any worse than it is. Just keep it in the back of your mind and replace it when it is convenient for you.

sleepstar · #5 08-06-2014, 01:47 PM

lucas products seem to work better than most other "miracle" cure products

shertex · #6 11-18-2014, 06:47 AM

Several thousand miles later, so far so good. I think my measurements were a little off in the early going (skewed high). With very careful measurements now (temp and fluid level), it looks like I go about 1600 miles before the fluid level drops from max to min level. And I've used not quite one 12 oz. bottle over the course of about 5000 miles.

My remaining question is, when the seals eventually fail permanently (necessitating replacing the rack), how rapid will the fluid loss be? Will it be slow enough that I can keep dumping power steering fluid in until I have time to replace the rack....or will it be worse than that?

leathermang · #7 11-18-2014, 08:57 AM

Fixing or slowing a leak in a rubber seal with chemicals which cause the rubber to expand is not in the snake oil category which the word ' miracle ' might imply.... I have told of my success with the front trans seal in my 95 Lincoln leaking a quart per 75 miles ten years ago... fixed with same repeated application of Trans-X..... it is still holding to this day.
But I feel very different about fixing leaks in metal objects... like radiators , heater cores, etc... which I worry have the potential for causing problems with flow of the liquid needed inside those types of items... the idea that something can be circulated inside something like that... and ..... mixed with either water or antifreeze.... AND UNDER PRESSURE coming out of a hole.... cure at the point of exit due to oxidation ... or whatever.... is very hard to trust....

Junkman · #8 11-18-2014, 10:34 AM

I would put a fix on my list, take a good deal on parts when they turn up and fix it when I can. Once fixed, it is off the to do list. Stop-gapped, it remains on the list and is a potential source of unreliability.

uberwasser · #9 11-18-2014, 10:42 AM

I've had similar success with stop leak. I had an '89 Suburban that was draining the reservoir every few days. I filled it up with stop leak and it never leaked again for the remaining years I had it.

So it depends on the car, and what you want to put in to it. If a box started leaking on my '85 I'd replace it. If it was leaking on my '79, as it stands, I'd probably stop leak it. Different cars, different priorities.

shertex · #10 11-18-2014, 10:47 AM

Quote:

Originally Posted by Junkman

I would put a fix on my list, take a good deal on parts when they turn up and fix it when I can. Once fixed, it is off the to do list. Stop-gapped, it remains on the list and is a potential source of unreliability.

You make a valid point. But, at $425 for the rack plus labor, it's nice to be able to delay it for a while....perhaps a long while. Trying to gauge the likelihood of catastrophic failure at some point....have some inquiries into some outfits that specialize in the MB steering systems, will report back if they have anything interesting to say.

shertex · #11 11-18-2014, 11:42 AM

The other question that occurred to me was the viscosity of the stuff and how it will handle very cold weather. So I'm thinking it might be wise to top off with regular fluid for the next several months.

leathermang · #12 11-18-2014, 11:54 AM

What do the instructions say to do ?

shertex · #13 11-18-2014, 12:25 PM

Quote:

Originally Posted by leathermang

What do the instructions say to do ?

To the best of my recollection, they simply say to keep topping off the reservoir....I don't know that they address the issue of cold weather.

Right now I've poured about 10 oz. of the stuff into a 40 oz. (I think) system.

leathermang · #14 11-18-2014, 01:29 PM

I am not sure how cold that fluid might be when it is going through the pump and the steering part.... but I would keep like five to ten percent by volume of the seal in the mix...
That is what I am doing with the Lincoln ... I mixed up some with trans fluid and keep that quart in the car... so when I add... which is like once a year.. I keep the same percentage in it....

barry12345 · #15 11-18-2014, 01:40 PM

The stuff is a seal softener and it expands them at the same time. I would grab a rack off of a low milage gasoline wreck and keep it on hand or change it out.

You have to drive a substantial distance before the seals get fully impacted by stuff like this. For example in an auto transmission 1500 miles is usually required to determine if the seals are fully impacted.

I would not expect a total failure of the seal eventually.. Rather a case of increasing leakage eventually. Not enough to make you have to flatbed the car in or it may be drivable with stiffer steering until you got to where you where going. Although in a situation like that I would take the belt off the power steering pump rather than run the power steering pump dry if the leak was too heavy.

If this was not possible because of belt configuration I would make it a plan to get a low milage rack in there. Not perhaps immediately but within a reasonable time frame.

If the stop leak had totally eliminated the problem one may take a chance. Still your car was not just sitting around allowing the seal to just dry out so total relief is not likely but still a possibility. Some more milage may tell the story. You have a worn seal rather than just a dried out one in my opinion.

Not much advantage with a brand new rack over a rack out of a truly low miles wrecked gas car. If the time comes.