Now the new cooler snapped right into place like it was made to go there. We could have installed an aftermarket fluid cooler, but going with the non-M5 E39 automatic transmission cooler is an extremely simple upgrade. No need to figure out a mounting solution for the cooler or how to route the plumbing. Easy!
We reassembled everything in the reverse order that we took it apart. The power steering feed and return lines will now sit a little bit lower than their original location, but there is plenty of play in the lines where this is a non issue. You can see the voids above the lines where the inlet/outlet of the the pipe cooler used to be. Without the stock air boxes in the way our new aluminum CSF radiator really shines. If you want to see our new cool CSF radiator, click here!
The last item on the list was to replace the power steering reservoir since it has a non serviceable built in filter. We once again reached into the McMaster-Carr parts bin for a quickie upgrade. We used part number 4403K81 for these orange high-temp vibration damping mounts to replace the worn and deformed stock ones. We had already used these on our oil filter housing a while back and they’ve been holding up great!
We finished the job by filling up our system with fresh Redline synthetic power steering fluid. Our new power steering cooler has so much more cooling capacity that we are confident we will likely never have another power steering overheating issue. Now it’s time to reassemble our car and test our new CSF radiator and Dinan cold air system on our dyno!
7 comments
Hold the phone, is that a mechanical/clutch fan for the engine? Have you considered an electric one which also would free up some space in that tight area? And the added benefits of freeing up a little HP.
We have definitely considered that and is on our list of upgrades. One thing at a time though 😉
Any real data(fluid temps) before and after?
Nope. This upgrade was prompted by the leaks we found during our radiator install. So we did not go through the process of gathering before data.
Well shoot, I should have done this on my ‘02 when I replaced the radiator.
I’ll add it to the list.
Great article but you really need to include the part number for the new cooler or at least what specific year and model E39 it’s from. The photo is not clear enough to read the full part number.
Agreed. Part numbers would have been great to add to the article. FWIW, the part number shown in the pic is 0159-1042.