89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
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18,682 Posts
Mine is jammed up, not pumping or buzzing with direct 12V . Replacement around $400............. nu-uh :nono: Not at least yet.
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DIY D-Jet Fuel Pump Rebuild
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89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
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18,682 Posts
Remove 4 flat tip screws
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89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
Joined
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18,682 Posts
Lift off gently and keep in an upright position.
Notice it's off center. When I removed the previous piece, it was stuck against one side of the wall.
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Notice it's off center. When I removed the previous piece, it was stuck against one side of the wall.
89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
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18,682 Posts
Remove outer ring. Good to check the condition of the lower gasket.
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89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
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18,682 Posts
Remove rollers
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89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
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18,682 Posts
Lift off gear
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89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
Joined
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18,682 Posts
Video of reassembly with a blooper at the end. Rotated the outer ring that surrounds the gear and rollers so that it cleared. It is essentric.
89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
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18,682 Posts
She lives. * Do not apply voltage no longer than I did, or you can burn the pump up due to the lack of lubrication and cooling the gasoline provides. *
'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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14,172 Posts
Just happens I have been doing exactly the same thing with the pump out of my '72 350SL.
Problem is that we can check the rotor part out, but not the internal part where the fuel flows through the motor.
I took the check valve off, filled the motor with carb cleaner and shook it. Did this a few times dumping the contents. Saw some stuff come out, but not much. I have heard of people running the pump backwards, but that would require a fitting in place of the check valve that would allow reverse flow.
My pump was working, but I thought it might be contributing to a hot start problem. The gas flows right by the internals of the motor, so if the windings are hot, they could cause the gas to vaporize, especially when tank level is low.
For anyone dismantling their pump, make notes or take pictures of the orientation of the parts. That little notch in the plate must be pointing the right way!
There are some aftermarket or rebuilt pumps (Airtex, Python, Walbro etc), but my guess is that they are not the same quality as the original Bosch. But, list on our pump is about $850 and best on-line price is about $450.
It seems to me that we should be able to use a pump meant for a K-jet car. The exit threaded fitting for the K-jet hard piped banjo fitting would have to be removed and replaced with an elbow that the check valve off the old pump will screw into.
I would like to find the technical spec for the D-Jet and K-jet pumps before I buy a pump. The test minimum flow for D-jets is 2L/min (30psi) and for K-jet 1.5 L/min. But the K-jet is pumping against a much higher pressure.
Her's a few pics of my pump project!
Overall arrangement - helps with re-assembly!
Check valve at discharge
3 pics of pump dis-assembly
Fuel damper (part 182 in drawing)
My pump was loose in bracket and hoses needed replacing, so at least I got that done!
Problem is that we can check the rotor part out, but not the internal part where the fuel flows through the motor.
I took the check valve off, filled the motor with carb cleaner and shook it. Did this a few times dumping the contents. Saw some stuff come out, but not much. I have heard of people running the pump backwards, but that would require a fitting in place of the check valve that would allow reverse flow.
My pump was working, but I thought it might be contributing to a hot start problem. The gas flows right by the internals of the motor, so if the windings are hot, they could cause the gas to vaporize, especially when tank level is low.
For anyone dismantling their pump, make notes or take pictures of the orientation of the parts. That little notch in the plate must be pointing the right way!
There are some aftermarket or rebuilt pumps (Airtex, Python, Walbro etc), but my guess is that they are not the same quality as the original Bosch. But, list on our pump is about $850 and best on-line price is about $450.
It seems to me that we should be able to use a pump meant for a K-jet car. The exit threaded fitting for the K-jet hard piped banjo fitting would have to be removed and replaced with an elbow that the check valve off the old pump will screw into.
I would like to find the technical spec for the D-Jet and K-jet pumps before I buy a pump. The test minimum flow for D-jets is 2L/min (30psi) and for K-jet 1.5 L/min. But the K-jet is pumping against a much higher pressure.
Her's a few pics of my pump project!
Overall arrangement - helps with re-assembly!
Check valve at discharge
3 pics of pump dis-assembly
Fuel damper (part 182 in drawing)
My pump was loose in bracket and hoses needed replacing, so at least I got that done!
Attachments
I just finished doing this, and when I applied voltage I did get a buzzing sound. But it wasn't as loud as Nutz'. If it wasn't turning, would I hear anything?
I didn't do a before test because I was worried about igniting gas still in there.
What is safe to pump through there for a test?
I didn't do a before test because I was worried about igniting gas still in there.
What is safe to pump through there for a test?
'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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14,172 Posts
You can use kerosene or diesel fuel or something like Varsol. I had two short pieces of hose- sucked out of a 1L yogurt tub and discharge straight back in again.
It would be best to hook it up to power without the rotor installed - Then you can see the spindle spinning and hear what it sounds like.
I first put mine back together with the intake in the wrong place. This jammed the rotor and the pump just made a humm. It could burn out if left like that for more than a few seconds.
Good Luck!
89 Mercedes 300E, 91 Mercedes 300CE, 71 BMW turbo 2002, 73 BMW 2002tii, 85 BMW 635csi
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18,682 Posts
Just be sure you don't run anything through it that contains methanol.
'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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14,172 Posts
Great!
What did that pump cost at Autozone?
Any idea of it specs? (Flow & max pressure)
25-35 gal/hr and 85-105 psi is what they say...
'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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14,172 Posts
Why were you worried about igniting gas in the pump when your car is a diesel??
BTW - I have an identical '85 300D - Great car!
there is indeed a diesel in my driveway, but the D-jet pump in question is from the 73 450SEL
'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
Joined
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14,172 Posts
Mathew - Do you know the model number of the pump and the price that Autozone sells it for?
I am in Canada, so want to check availability and price up here before driving over to Autozone.
Existing pump is working, but it would be good to have a spare.
Airtex E8145. Cost me 219.00, I think.
Pierre, who runs a MB shop down in Titusville, told me today that most aftermarket pumps don't do a good job with the PSI and volume requirements of D Jet. The numbers look fine on the upper end, but possibly low delivery volume on the lower end. I'll do a test to see if I get 2L/min soon.
Pierre gave me two old pumps and I might end up with a frankenpump from the three cores I now have...assuming the numbers don't add up on the aftermarket one. when I test it. I'll need to get a gauge to check pressure too. have any thought there?
Pierre, who runs a MB shop down in Titusville, told me today that most aftermarket pumps don't do a good job with the PSI and volume requirements of D Jet. The numbers look fine on the upper end, but possibly low delivery volume on the lower end. I'll do a test to see if I get 2L/min soon.
Pierre gave me two old pumps and I might end up with a frankenpump from the three cores I now have...assuming the numbers don't add up on the aftermarket one. when I test it. I'll need to get a gauge to check pressure too. have any thought there?
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