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FCP Euro Service Kits

FCP Euro Kits

The early Mercedes 450SL power steering system is very robust and quite simple. The other positive is, pumps, hoses, steering boxes etc., are all available should the need arise.

Several things that all power steering systems need on a regular basis is to be checked for fluid. While the power steering pump does not rely so much on the fluid for lubrication but more so for generating the power necessary to turn the steering wheel more easily and remove some heat. Power steering shows its true value when the car is stationary and the wheels must be turned, for example in a parking lot. If you have ever driven a car without power steering, you will fully understand the incredible amount of effort it takes to turn the wheel at a stand still.

When preparing the power steering pump to be returned to the 1975 450SL, I wanted to be sure the system was in good shape. Having had the opportunity to drive the car prior to the timing chain replacement and the car being taken out of service for a few months, I noticed the power steering was quiet and felt as it should. The only check I did of the system when I purchased the car, was to make sure there was plenty of fluid and that the fluid was not black.

With the power steering pump out, I was able to check it thoroughly and all looked good and leak free. The power steering hoses appear to be ok, but will be replaced, both high and low pressure. The hoses appear to be original and it is safe to say they have served their time very well and can now rest in peace.

As with all fluids and as mentioned in past articles, follow your owners manual for the proper power steering fluid for your model. In the case of the ’75 450SL, Mercedes-Benz manual states “ATF Type A Suffix A (if not available use Dexron).” Yes you read that correctly. With that, I was not familiar with “ATF Type A Suffix A, so it was time to call an expert. I contacted Ken at Acclaim Transmission who also happened to rebuild the transmission in my 1965 Rolls-Royce Phantom V. With decades of experience on classic transmissions, Ken suggested that even if the “Type A Suffix A” ATF could be located, it would not be a good choice at this point. One of the drawbacks of the Type A, is its inability to cool properly under high heat conditions such as it is here in the Desert Southwest. His recommendation is to use the easily available Dexron III which will be the same fluid that would be used for the transmission or you can use a Dexron III compatible fluid.

I have chosen to use the Redline power steering fluid as I have had great experience with that in my Rolls-Royce power steering unit for years now. Brands that will serve the system very well are, Red Line Power Steering Fluid, Castrol Dex/Merc, Valvoline Dex/Merc, Febi Power Steering Fluid and Mercedes-Benz Power Steering Fluid.

Should your unit be noisy however, you are most likely looking at low fluid, potentially very dirty fluid, worn pump or air in the system.

If it is necessary to rebuild your pump however, you will need a puller, similar to the model shown. This puller will be needed to remove the “hub” from the unit. IMPORTANT: DO NOT use a claw type puller or you will ruin the flange. Also be sure not to lose the woodruff key when disassembling.

When inspecting my pump, I discovered several things. One, the filter was disintegrating and obviously very old and filthy. Second, I noticed about a teaspoon of very sticky sludge in the reservoir recesses as indicated in the photo. 95% of the crud was scooped out by using the head of a small long handled screwdriver. Those areas were then cleaned out with some fresh ATF.

Working over a small tub, I also poured about a cup of ATF in the unit with my finger over the low pressure return hose port. I then rotated the pulley assembly clockwise to remove any old fluid that had remained in the pump itself.


At the end of that process, drain all remaining fluid and properly dispose of it.

Now the unit is ready to be washed down well with a degreaser and prepped for a touchup of paint. NOTE: be sure to cover the name plate on the front of the unit if you wish to keep that intact. Any harsh cleaners will wash the printing (paint) off the metal ID plates and leave them free of any markings. To protect the plate, I use two layers of painters tape and trim the edges with a new razor blade. Be sure the tape is firmly pressed down to create a leak proof seal.

Once the housing is brushed, scraped, and cleaned properly and the various parts are taped up, it is ready for paint. I use semi-gloss for the body and gloss for the pulley and cap as appears to have originally been done from the factory. As you can see, the original wing nut was replaced by a homemade device by the previous owner, which I have since replaced. If you are stuck for random parts, ACE Hardware is a very good resource.


 

With the pump clean and painted, it is ready to be reinstalled and filled. Always be sure to monitor fluids for proper levels and cleanliness and change your filters. Always change at prescribed intervals, as directed by your owners manual.

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Written by :
West Kenyon

West Kenyon is a Multi-Media Design Consultant and automotive enthusiast. Cars in his collection include a 1956 Austin FX3-D, better known as a London Taxi, a 1965 Rolls-Royce Phantom V, and a 1975 450SL and 1981 240D by none other than Mercedes-Benz. West said, “owning one or a number of vintage cars is often an expensive proposition", which is why he does the majority of mechanical and interior work/restoration himself. West added, “not only does it save a significant amount of money to do the work yourself, it also provides full opportunity to know the job is being done with excellence and allows for an unprecedented appreciation and knowledge of the car.” For FCPEuro, West will focus on providing in-depth information on both the Mercedes-Benz R107, 450SL, D-Jetronic version and the W123, 240D. Glücklich Autofahren! (Happy Motoring)


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