2007 GL450 Power Steering Pump replacement procedure?
10-15-2014, 03:10 PM
#1
Junior Member
Thread Starter
2007 GL450 Power Steering Pump replacement procedure?
Can anyone share the procedure for the power steering pump replacement on the 2007 GL450? Thank you.
Problem: Steering very stiff at Idle only. Much Better, quite normal while barely moving or engine revved up at slightly higher RPMs while still stationary with transmission in "N"eutral.
Checked Steering fluid level. Found it quite low. Purchased and added Steering Fluid from MB dealership. Drove about 20 miles. Turned a dozen times lock-to-lock left and right. Fluid level stayed good. No improvement.
Some background: This car had a leaky Steering Reservoir "O" Ring. Reservoir was replaced at MB dealership about 9 months ago. No signs of leaks since then. Not sure why steering fluid level dropped at all.
To "bleed" the system, I jacked the car up, front wheels in the air, turned wheels left and right, lock to lock, about 30 times. Some fluid leaked onto the floor. Seems to have overflowed from the open reservoir. I must have turned the wheel perhaps a little too fast. Replenished/topped off steering fluid again. Turned a few more times, slower this time. Still overflowed a bit. Topped off fluid one last time.
I was hoping this bleeding procedure would let out any air that may be trapped in the system. Whether it did that or not, it did not help the steering problem.
I have since purchased a replacement steering pump that I'll be installing in the next few days. Looking for a procedure instead of just figuring out on the fly.
Thank you
Power Steering Fluid Part Number: Q1460001
Problem: Steering very stiff at Idle only. Much Better, quite normal while barely moving or engine revved up at slightly higher RPMs while still stationary with transmission in "N"eutral.
Checked Steering fluid level. Found it quite low. Purchased and added Steering Fluid from MB dealership. Drove about 20 miles. Turned a dozen times lock-to-lock left and right. Fluid level stayed good. No improvement.
Some background: This car had a leaky Steering Reservoir "O" Ring. Reservoir was replaced at MB dealership about 9 months ago. No signs of leaks since then. Not sure why steering fluid level dropped at all.
To "bleed" the system, I jacked the car up, front wheels in the air, turned wheels left and right, lock to lock, about 30 times. Some fluid leaked onto the floor. Seems to have overflowed from the open reservoir. I must have turned the wheel perhaps a little too fast. Replenished/topped off steering fluid again. Turned a few more times, slower this time. Still overflowed a bit. Topped off fluid one last time.
I was hoping this bleeding procedure would let out any air that may be trapped in the system. Whether it did that or not, it did not help the steering problem.
I have since purchased a replacement steering pump that I'll be installing in the next few days. Looking for a procedure instead of just figuring out on the fly.
Thank you
Power Steering Fluid Part Number: Q1460001
Last edited by galileo55; 10-23-2014 at 11:27 AM.
10-20-2014, 11:21 AM
#3
Junior Member
Thread Starter
Things took a "turn" for the better after I replaced the pump with a brand new one. For this troubleshooting, I bought a $150 (including shipping from Hong Kong) Chinese-made pump online rather than a $500 German-made. With the new pump, it's much easier now to turn the wheels when stopped. However, it's not quite 100% perfect. Still occasionally and intermittently gets stiff while parked but only after driving for a while, and not every time.
The pump replacement was easy enough:
Removed engine cover, air intake big hoses, water cooling hose from top of radiator.
Pumped steering fluid out of reservoir, did not disconnect special clamp/hose from reservoir, set reservoir to the side, removed somewhat hard-to-get-to partially hidden 3 Torx screws on front of reservoir , removed C-shaped clamp from back of reservoir to pump (used a screw driver, careful not to damage reservoir plastic when removing it from pump - pulled reservoir straight out while gently wiggling it clockwise and counter-clockwise (but not side to side), after totally loosening removing screws from reservoir. Screws stay on reservoir after loosening. They do not come off, to avoid losing them.
Removed the hose from the pump (goes to steering rack, right side as you look at pump), careful not to lose the copper compression O-Rings (2 of them, one on each side). Looked at 6 auto parts and special shops near my house for replacement rings. No luck. My hose was missing one of the rings. I finally stopped by a mechanic's next door and got an Aluminum ring that he happened to have of the exact same size. Used the old copper and one of aluminum.
Turned serpentine belt tensioner counter-clocksize (17mm socket on partially blocked from view built-in bolt on tensioner), took belt off pump pulley.
Removed 3 large bolts (two front, one in back) from pump. Removed Pump. Put in cloth to avoid dripping all over.
Installed the new pump. Used the old rubber O-ring between Reservoir and Pump. It was thicker and wider and fit better than the 2 simple O-rings that came with the Chinese pump. My old rubber O-Ring was relatively new with reservoir replaced just a few months ago.
Reconnected radiator hose, topped off radiator coolant with 50/50 mixture. Put the belt back onto the pump pulley.
Filled power steering reservoir with MB power steering Q1460001. Raised front wheels, ignition in position 2, turned wheels lock to lock slowly a few times. Level stayed the same. Turned a few more times, a little faster. Fluid overflowed out of top of reservoir. I had bought 3 x 1 Liter Steering Fluid but I only needed 1 liter, with some left over.
Turned car on, added coolant again. Checked power steering fluid level, added a little more, put car back down. Drove in neighborhood. Coolant level warning came on, topped it off one last time.
Checked power steering level, it was too full. Pumped some out with clean pump hose. Fluid seemed a bit clearer/cleaner now. Not as dark.
Checked level again this morning after driving about 30 miles. Still good.
However... to me, the steering effort still feels a little heavier than I believe it should when totally stationary. My other MBs (E350, E55) feel a lot easier to turn when parked but they don't weight as much. Not quite sure what "Normal" should be on this GL450.
The dealer wanted to change the rack (~$2000), the pump (~$600), Plus Labor & Tax. Did not get a quote for labor. Overall, I feel this DIY was worth it ($150 + about 5 hours of super careful work. Perhaps 2-3 hours next time).
Keeping fingers crossed I won't need a new rack soon. The steering system is making a very slight groaning noise when locked to one side or the other. I'm hoping that's just normal.
Cheers!
The pump replacement was easy enough:
Removed engine cover, air intake big hoses, water cooling hose from top of radiator.
Pumped steering fluid out of reservoir, did not disconnect special clamp/hose from reservoir, set reservoir to the side, removed somewhat hard-to-get-to partially hidden 3 Torx screws on front of reservoir , removed C-shaped clamp from back of reservoir to pump (used a screw driver, careful not to damage reservoir plastic when removing it from pump - pulled reservoir straight out while gently wiggling it clockwise and counter-clockwise (but not side to side), after totally loosening removing screws from reservoir. Screws stay on reservoir after loosening. They do not come off, to avoid losing them.
Removed the hose from the pump (goes to steering rack, right side as you look at pump), careful not to lose the copper compression O-Rings (2 of them, one on each side). Looked at 6 auto parts and special shops near my house for replacement rings. No luck. My hose was missing one of the rings. I finally stopped by a mechanic's next door and got an Aluminum ring that he happened to have of the exact same size. Used the old copper and one of aluminum.
Turned serpentine belt tensioner counter-clocksize (17mm socket on partially blocked from view built-in bolt on tensioner), took belt off pump pulley.
Removed 3 large bolts (two front, one in back) from pump. Removed Pump. Put in cloth to avoid dripping all over.
Installed the new pump. Used the old rubber O-ring between Reservoir and Pump. It was thicker and wider and fit better than the 2 simple O-rings that came with the Chinese pump. My old rubber O-Ring was relatively new with reservoir replaced just a few months ago.
Reconnected radiator hose, topped off radiator coolant with 50/50 mixture. Put the belt back onto the pump pulley.
Filled power steering reservoir with MB power steering Q1460001. Raised front wheels, ignition in position 2, turned wheels lock to lock slowly a few times. Level stayed the same. Turned a few more times, a little faster. Fluid overflowed out of top of reservoir. I had bought 3 x 1 Liter Steering Fluid but I only needed 1 liter, with some left over.
Turned car on, added coolant again. Checked power steering fluid level, added a little more, put car back down. Drove in neighborhood. Coolant level warning came on, topped it off one last time.
Checked power steering level, it was too full. Pumped some out with clean pump hose. Fluid seemed a bit clearer/cleaner now. Not as dark.
Checked level again this morning after driving about 30 miles. Still good.
However... to me, the steering effort still feels a little heavier than I believe it should when totally stationary. My other MBs (E350, E55) feel a lot easier to turn when parked but they don't weight as much. Not quite sure what "Normal" should be on this GL450.
The dealer wanted to change the rack (~$2000), the pump (~$600), Plus Labor & Tax. Did not get a quote for labor. Overall, I feel this DIY was worth it ($150 + about 5 hours of super careful work. Perhaps 2-3 hours next time).
Keeping fingers crossed I won't need a new rack soon. The steering system is making a very slight groaning noise when locked to one side or the other. I'm hoping that's just normal.
Cheers!
Last edited by galileo55; 10-23-2014 at 11:29 AM.
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texas008 (04-18-2024)
10-20-2014, 05:44 PM
#4
Junior Member
Thread Starter
Thanks. Used them before. Great price but can't put up with having to print one page and one enlarged photo at a time. It's easier to just do the work than to print from their site :-)
12-02-2014, 02:08 PM
#5
Newbie
Thanks for PS Pump Replacement Procedure!
Many thanks to galileo55 for posting the procedure to replace the PS pump. I performed this replacement over the weekend with success. Some additional observations for those considering this replacement:
1) I was advised to replace the reservoir at the same time I replaced the pump. I used a Duralo 204-1005 replacement pump ($240) and a Mercedes w164 w463 450 550 Power Steering fluid Reservoir w463 ($70). Purchased both via Amazon, as well as Pentosin CHF202 PS fluid.
2) The PS reservoir is easy to remove as described (use the replacement for clues where to find the mounting bolts, two of which are hidden from view). The pump took a little head-scratching. In hindsight, it is exactly as galileo55 described - two bolts in front, and one in the back, but they're a bit hard to find the first time.
3) My choice of pump required reuse of a mounting bracket from the old pump. Once I removed the OEM pump, I had to pull the pulley and remove this bracket, pull the pulley on the new pump, affix the mounting bracket, and remount the pulley. Not a big deal, but be prepared.
4) My PS pump did not come with an O-ring for the connection to the PS reservoir, and I could not reuse the one from the OEM pump as I had hoped. I had to get one from an assortment in the HELP! section of the auto parts store. Works fine, no leaks, but I should have checked before I started.
5) Getting the C-clamp that affixes the PS reservoir to the pump back on was a bit of a challenge. Should I be ashamed to say that once I put the clip in position, I used my breaker bar with the 17mm socket to cradle the clip and pop it home?
Helpful stuff to have/things to know/remember:
- I used my 24" breaker bar with a 17mm socket to hold belt tensioner in place temporarily while removing/installing the pump. Handle fits under the hood nicely. Your methods may vary, and at your own risk of course
- The PS pressure hose is a 22mm socket. Mind the compression bushings.
- The PS pump mounts with 3 each star head bolts, either E10 or E12 as I recall
- The PS pump mounting bracket that I described uses 3 each T40 bolts
- You'll need blue locktite to reattach the pump mounting bolts. May want to check and see if that bottle in your tool box hasn't already dried up before you start work. Ask me how I know.
- I rented pulley removal/installation toolset from AutoZone for next to nothing. $40 deposit
I concur with the time/effort estimate that galileo55 suggested. If I had to do this job again, I could probably do the whole thing in 2-1/2 hours now that I know what I need and where everything is. Allow extra time for unplanned trips to auto parts store, fishing around in the dark for that E12 socket that you dropped, etc.
Happy wrenching
1) I was advised to replace the reservoir at the same time I replaced the pump. I used a Duralo 204-1005 replacement pump ($240) and a Mercedes w164 w463 450 550 Power Steering fluid Reservoir w463 ($70). Purchased both via Amazon, as well as Pentosin CHF202 PS fluid.
2) The PS reservoir is easy to remove as described (use the replacement for clues where to find the mounting bolts, two of which are hidden from view). The pump took a little head-scratching. In hindsight, it is exactly as galileo55 described - two bolts in front, and one in the back, but they're a bit hard to find the first time.
3) My choice of pump required reuse of a mounting bracket from the old pump. Once I removed the OEM pump, I had to pull the pulley and remove this bracket, pull the pulley on the new pump, affix the mounting bracket, and remount the pulley. Not a big deal, but be prepared.
4) My PS pump did not come with an O-ring for the connection to the PS reservoir, and I could not reuse the one from the OEM pump as I had hoped. I had to get one from an assortment in the HELP! section of the auto parts store. Works fine, no leaks, but I should have checked before I started.
5) Getting the C-clamp that affixes the PS reservoir to the pump back on was a bit of a challenge. Should I be ashamed to say that once I put the clip in position, I used my breaker bar with the 17mm socket to cradle the clip and pop it home?
Helpful stuff to have/things to know/remember:
- I used my 24" breaker bar with a 17mm socket to hold belt tensioner in place temporarily while removing/installing the pump. Handle fits under the hood nicely. Your methods may vary, and at your own risk of course
- The PS pressure hose is a 22mm socket. Mind the compression bushings.
- The PS pump mounts with 3 each star head bolts, either E10 or E12 as I recall
- The PS pump mounting bracket that I described uses 3 each T40 bolts
- You'll need blue locktite to reattach the pump mounting bolts. May want to check and see if that bottle in your tool box hasn't already dried up before you start work. Ask me how I know.
- I rented pulley removal/installation toolset from AutoZone for next to nothing. $40 deposit
I concur with the time/effort estimate that galileo55 suggested. If I had to do this job again, I could probably do the whole thing in 2-1/2 hours now that I know what I need and where everything is. Allow extra time for unplanned trips to auto parts store, fishing around in the dark for that E12 socket that you dropped, etc.
Happy wrenching
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texas008 (04-18-2024)
02-19-2018, 02:57 AM
#6
I know this is an older post but Thanks to galileo55 and dr_crockett for posting this. VERY useful when doing my power steering pump replacement this past weekend. Took me just over 2 hours which is surprisingly long considering how simple of a job this is.
A couple notes to add to these posts.
- Remove the front belly pan so you can catch coolant when disconnecting the top radiator hose.
- A turkey injector syringe was quite useful for adding or removing small amounts of PS fluid (Pentosin CHF 11S)
A couple notes to add to these posts.
- Remove the front belly pan so you can catch coolant when disconnecting the top radiator hose.
- A turkey injector syringe was quite useful for adding or removing small amounts of PS fluid (Pentosin CHF 11S)
02-20-2018, 12:10 PM
#7
Newbie
Glad it helped!
I know this is an older post but Thanks to galileo55 and dr_crockett for posting this. VERY useful when doing my power steering pump replacement this past weekend. Took me just over 2 hours which is surprisingly long considering how simple of a job this is.
A couple notes to add to these posts.
- Remove the front belly pan so you can catch coolant when disconnecting the top radiator hose.
- A turkey injector syringe was quite useful for adding or removing small amounts of PS fluid (Pentosin CHF 11S)
A couple notes to add to these posts.
- Remove the front belly pan so you can catch coolant when disconnecting the top radiator hose.
- A turkey injector syringe was quite useful for adding or removing small amounts of PS fluid (Pentosin CHF 11S)
I live in Houston and flooded out all of the electronics modules + audio that sit in wells below the floorboards. Replaced and reprogrammed all of that. More on that adventure in another post!
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texas008 (04-18-2024)
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02-21-2018, 01:03 AM
#8
I also replaced the rack later with an aftermarket version. As I recall, you have to remove the front axles and drop the front differential to get in there. Sphincter factor of about 8/10, but actually really straightforward
I live in Houston and flooded out all of the electronics modules + audio that sit in wells below the floorboards. Replaced and reprogrammed all of that. More on that adventure in another post!
I live in Houston and flooded out all of the electronics modules + audio that sit in wells below the floorboards. Replaced and reprogrammed all of that. More on that adventure in another post!
Sorry to hear you had flooding from Harvey but glad your GL is back up and running. Hope your house faired better.
