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Heat is the enemy of spring steel and with heat cycling, spring steel will lose its spring strength.
High heat affects the springiness of spring steel, but the temperature at which this occurs is way higher than the heat present under the hood. The hose would melt at the temperature necessary to relax spring steel. I've reused spring clamps my whole life without issue. On the other hand, if some grease monkey got a hold of the clamp and deformed it in any way, by all means replace it post haste!
...I also have a secret weapon in case the old clamps are too loose. - my Clamptite hose clamp making tool.
I wouldn't use this method/tool except for emergency repairs. The risk of under/over tightening is too great. And, while it looks cool in the demo, it's practical application under the hood seems limited to me. Is it better than a worm-gear clamp--yes. Is it better than an OEM spring clamp--no.
Got the job completed. Old clamps were in good shape. So no need for special maneuvers.
Took quite a bit longer than planned, mostly due to the old hoses being so badly hardened. They twisted free easily, but pulling them off was a bear. Their narrow, now hardened ends would not readily slide past the flanged portion of the fittings. Picts and helpful hints to follow....
As there are already good power steering flush DIY's available, I'll mostly fill in the gaps.
Process began with suctioning out as much ATF from the power steering reservoir as possible. Refilling to the cold max line then takes about 1/2 can of the Seafoam Transtune.
Because the engine needs to idle and one must periodically move the front wheels, circulation of the Transtune was done outdoors on my driveway. I didn't want to mark up my driveway with turning the wheels. Nor did I want to wear a spot on my tires.
Use two layers of cardboard with a plastic bag between them as make-shift turn plates. The were pretty worn by the end of 30 minutes circulation time with me slowly turning lock to lock every couple minutes.
I went a little longer and with more frequent steering motion to maximize Transtune circulation. Risk would be more exposure of seal to Transtune, but nobody seems to be reporting destruction of their racks and Scotty Kilmer claims to have added it to a lot more steering racks than all of us combined.
Once circulation was complete, back into the garage and lifted up on my QuickJacks. I use them often, but am always cautious to avoid false lock and add a set of jack stands as backup.
Remove air intake box and front engine undercover. You can't get this job done with those in place. Be careful with the MAF sensor cables. Also, there is a point in the process where you turn key to on with MAF still disconnected. That triggers a VSC /Engine check lights and you will need to do the VSC reset procedure via the OBD connector at the end of all the work.
Lay out LOTS of rags to catch the inevitable ATF spillage. Be sure to cover the alternator as well. That is easiest to do from below.
Speaking of below, here is the bottom end of the return line. It dives down and is nigh impossible to see from above due to the power steering vacuum lines. From below, you can see it, but some hard lines partially block your access. In this pict, my flashlight is in upper left and camera is looking up. The blue is my front sway bar bushing. Hiding up there above the intervening hard line is the bottom end of the return line (green arrow).
I found it easiest to manipulate its clamp with medium length, needle nose, vice grips from below. Did not have enough grip power to use regular needle nose pliers due to the awkward and limited access.
The rest of the clamps were easily loosened with 90 degree or straight needle nose pliers.
Once all clamps were loosened and slip off the fittings, it was easy to break the hoses free by twisting with hose pliers. At that point, it was very clear just how loose the hoses had become. They could pivot quite freely. No hose rubber elasticity remained to grab the fittings. It was all clamp pressure making the seal.
Unfortunately, their freely pivoting did NOT also mean they were easy to pull off their nipples. Each hose had become so rigid that they strongly resisted stretching back over the nipple flares.
The reservoir nipples are plastic and I took great care to limit forces that could snap them. The sequence worked was....
1. Suction as much ATF out of reservoir as possible. Free the reservoir from its bracket and you can tilt it towards front of car to permit removal of some more ATF. There will still be a mess, but you have rags spread to sop it up.
2. Remove the bottom end of supply hose at power steering pump. Plug the power steering nipple with cutoff, smallest glove finger to avoid continual seepage. Note which way your return hose goes. It will fit both ways. I didn't notice when I did mine so I lost orientation. I put the shorter elbow end on bottom to better clear the airbox.
3. Tilt the entire reservoir forward about 90 degrees (toward front of car) now that it is freer to move.
4. Grasp and pull / twist back/forth each hose to remove from reservoir nipples. Set reservoir aside to be cleaned. It WILL drip ATF. Heck everything drips ATF. It's a messy messy job made tolerable only by copious layers of rags to catch the spillage. (Don't forget to cover your floor too)
Now all that is left is the bottom end of the return line. It's buried deep and I certainly could not muscle it off its hard line. Also, I did not want to stress the hard line and damage it. Twisting the hose readily popped stiction, but there was no budging it off the hard line no matter how I tried to wiggle and pull. My hands are pretty small and even I could barely reach in and get a grip. It's just plain awkward from above or below.
Some have cut the hose using a blade, but that risks damaging the hard line's surface. I opted to use my pencil slim, TS100 soldering iron set to 450C degrees. That is hot enough to melt the hose, but won't harm the hard line with a hard, sharp edge.
Not the greatest camera angle, but you can see me melting through the rubber with the T100. I advise starting at the far end of the hose and working towards the center of the hose. You want to weaken the hose as much as possible before punching through the hose into ATF. Once ATF starts trickling into your thermal "cut," things get really messy and slow.
With the hose end weakened by the T100 slitting through much of the hose end, I could finally wiggle and pull off the hose without unduly stressing the hard line.
Have an earplug ready to plug the hard line. It's going to release a fair amount of ATF once the hose is disconnected.
I removed and cleaned the return hose's foam and spiral wrap for re-use. New Gates power steering line was cut to about an inch longer than the original.
Pushing the hoses back onto their fittings was pretty easy. If the nipple was already flooded with ATF, that served as the lubricant. On the reservoir, where the plastic nipples were dry, I sprayed some alcohol to make the hoses easy to push on.
Note: Don't clamp the reservoir end of the lines until you have them twisted to minimize stress. Once, the clamp is on, the hoses can be locked in a stressed rotation. You don't want that.
Because I was also needing to flush the Transtune out, I connected the return line via a barb fitting to a long 3/8 inch vinyl tube running to waste pitcher.
Flushing was done with key in on position (engine not started). Lock to lock steering wheels x 2 was about one reservoir of fluid replacement. Don't let the reservoir go dry.
This is the step where MAF is disconnected but key turned on --> VSC error later.
My ATF was already pretty red even before this process because I had already exchanged it a few months ago. To get most of the Transtune out, I ran nearly a gallon of ATF through. Reserved about 1/8 gallon for final leveling.
Yes, nice and red
Put return line on reservoir, filled to cold max and began air purge.
I purged by doing about 50 lock to lock with engine off. Even so, with engine running after that, there was initially some intermittent, mild steering wheel stutter with engine on lock to lock. Pump never made any screeching noises, but I'm sure a little air was still being cleared out. Air inevitably gets into the system with hose changes.
Maybe we should be vacuum purging instead of just multiple engine off lock to locks.
Rechecked fluid levels and buttoned her up.
Last edited by Seattle SCone; Mar 14, 2021 at 03:05 AM.
I estimated three hours but took six. Wasted an hour seeing if possible leaving air box in place. Most time intensive was finding best way to detach hoses.
Was too tired after yesterday's session. After a good night's rest, I did a little more work to put aside my doubts about purging the power steering of air.
Also, was in better mental condition to evaluate how the steering is behaving
Put car back up on QuickJacks and did another 50 medium speed lock to lock turns of the steering.
Then out on road to do a couple lock to locks, with engine running,
a) on level road
b) hill with car pointed downhill
c) hill with car pointed uphill.
No more stutter events noted today and I'm now satisfied with the purge sequence being effective.
Steering was smooth before the project, but it is now glassy smooth and takes noticeably less effort to turn steering wheel. Just need one finger to turn spin the steering wheel post the flush. Whereas before Iit was more a two finger spin.
Flushing out the system with Transtune yielded a nice bonus on top of the main objective of changing out the seeping hoses.
The power steering has a pressure sensitive valve that increases airflow to the engine via those vacuum lines. This happens when steering fluid pressure goes up at left or right lock. The increased throttle prevents engine stall at steering lock.
BTW, that pressure sensitive air valve can fail. If that occurs, the vacuum pulls steering fluid into engine intake. The part is available separate from power steering pump, but I did not try to replace it.
Last edited by Seattle SCone; Mar 16, 2021 at 09:57 AM.
The power steering has a pressure sensitive valve that increases airflow to the engine via those vacuum lines. This happens when steering fluid pressure goes up at left or right lock. The increased throttle prevents engine stall at steering lock.
BTW, that pressure sensitive air valve can fail. If that occurs, the vacuum pulls steering fluid into engine intake. The part is available separate from power steering pump, but I did not try to replace it.
Just a question from a relatively new guy. ATF in the power steering system? Not power steering fluid? My Benz uses a hydraulic fluid in the power steering system. Also, where is the filter? Again, my R107 has a filter in the reservoir.
