help and suggestions needed. SMG issue journey

[chalaka]

It is definitely fixable. I do not re-oil, the pump, i try to keep it as dry as possible when assembling, once assembled and secure to pump body, before putting back the tiny filter, i drop some chf11s into the tiny hole, then rotate the pump manually from the shaft on where the electric motor the goes, this would give it some fluid so its not dry.

hope this helps..

your experience sharing definitely helps tons.

I'll try to redo my work and follow all the steps suggested ~

[Mattman928]

Did you ever resolve your issues?

Hope you don't mind if I hijack the thread, but I'm struggling with my SMG system. I replaced the SMG pump assembly last year. This winter I had to replace the clutch and the starter. When I put the system back together, the pump keeps running intermittently. With the key in the ignition, the pump runs for about 4 seconds, builds pressure, then turns off, the pressure leaks down over 10 seconds, and the pump comes on again. I monitored pressure on INPA and the pump is running wonderfully and building pressure, the system just can't seem to maintain the pressure.

I have removed the intake and checked above pump assembly as well as under the car around the transmission and see no evidence of a leak.

Could air be entering the system? The relay and pump seem to be working perfectly. When I removed the transmission, I disconnected the hydraulic lines from the pump housing. I did remove the Clutch slave cylinder to put a new boot on it. Other than the SMG system was not touched.

Where could air be entering the system? Any other thoughts? Any ideas would be welcome, I am very very frustrated.

[oceansize]

Did you replace the SMG pump with a brand new BMW unit?

[chalaka]

Did you ever resolve your issues?

Hope you don't mind if I hijack the thread, but I'm struggling with my SMG system. I replaced the SMG pump assembly last year. This winter I had to replace the clutch and the starter. When I put the system back together, the pump keeps running intermittently. With the key in the ignition, the pump runs for about 4 seconds, builds pressure, then turns off, the pressure leaks down over 10 seconds, and the pump comes on again. I monitored pressure on INPA and the pump is running wonderfully and building pressure, the system just can't seem to maintain the pressure.

I have removed the intake and checked above pump assembly as well as under the car around the transmission and see no evidence of a leak.

Could air be entering the system? The relay and pump seem to be working perfectly. When I removed the transmission, I disconnected the hydraulic lines from the pump housing. I did remove the Clutch slave cylinder to put a new boot on it. Other than the SMG system was not touched.

Where could air be entering the system? Any other thoughts? Any ideas would be welcome, I am very very frustrated.

Hi~
i have fixed my smg (i believe), have been DD with it for over 2000kms ..
i took apart everything, and re-torque the inner pump bolts,

additional work was on the "pressure relief valve" o-ring, i replace that small o-ring during my reinstall,
so i pass the bleeding steps right away,

quick notice after re-work was, motor primes up very quickly and healthy..

hope it lasts ..

[chalaka]

Did you replace the SMG pump with a brand new BMW unit?

I just took apart my old one and replaced the o-rings bought from MLR ..

i also replaced the pressure accumulator bought from MLR as well ..

[eacmen]

I just took apart my old one and replaced the o-rings bought from MLR ..

i also replaced the pressure accumulator bought from MLR as well ..

You mean the pressure accumulator on the pump right? There is no accumulator on the actuator afaik.

Did the MLR accumulator fail?

Were you fixing any specific issues when replacing the actuator seals? Did they get fixed?

[chalaka]

Did you ever resolve your issues?

Hope you don't mind if I hijack the thread, but I'm struggling with my SMG system. I replaced the SMG pump assembly last year. This winter I had to replace the clutch and the starter. When I put the system back together, the pump keeps running intermittently. With the key in the ignition, the pump runs for about 4 seconds, builds pressure, then turns off, the pressure leaks down over 10 seconds, and the pump comes on again. I monitored pressure on INPA and the pump is running wonderfully and building pressure, the system just can't seem to maintain the pressure.

I have removed the intake and checked above pump assembly as well as under the car around the transmission and see no evidence of a leak.

Could air be entering the system? The relay and pump seem to be working perfectly. When I removed the transmission, I disconnected the hydraulic lines from the pump housing. I did remove the Clutch slave cylinder to put a new boot on it. Other than the SMG system was not touched.

Where could air be entering the system? Any other thoughts? Any ideas would be welcome, I am very very frustrated.

so yours is not holding up pressure, at least the symptom is clear.

if you have been worked on the smg related LINEs .. and the clutch slave cylinder .. perhaps leaks are these areas related..

have you been able to go through all the bleeding steps from INPA? run it several time can take away the air in the line concern,
if still loosing pressure, then you can continue checking on the pump itself ..

since your pump is newly installed for 1 year only, if without touching it, wondering what could give up so quickly ..

(1) did you loosen the smg line from the pump side or the clutch side, are those screws tight enough?
(2) slave cylinder .. this part i am not familiar with, but fluid flows to here, are those tight?

if they are all checked, maybe pump itself is somehow just leaks internally .. man, for the last step, you might just need to check for those ..
or try run the accumulator pressure test as well .. at least to take out one more variable.

[chalaka]

You mean the pressure accumulator on the pump right? There is no accumulator on the actuator afaik.

Did the MLR accumulator fail?

Were you fixing any specific issues when replacing the actuator seals? Did they get fixed?

yea, the big rod like accumulator, my original symptom was dropping out of gears ..
car can't hold up pressure, and it's in a clear pattern .. when car gets hot, driven for like 10 minutes, dropped out of gear from 3 to N, then after a while (felt like pressure has build up enough) , car pops back to 3 ..
then eventually time gets longer, i can't get into gears no more.

so my 1st assumption was the pressure accumulator, i bought one, and decided to change it along with the inner seals just for the peace of mind..

then i noticed improvement on pressure build up speed/sound .. then car still drop out of gear, but it was holding up longer..
then i got suggestions from MRL about inner pump torque .. 7nm makes big difference here i guess. ..

[oceansize]

then i got suggestions from MRL about inner pump torque .. 7nm makes big difference here i guess. ..

As in MLR told you to torque to 7nm?

[chalaka]

As in MLR told you to torque to 7nm?

Hi,
Yes,
also info on this page which i found out later

https://mlreng.com/blogs/news/e46-m3-smg-pump-torque-spec?srsltid=AfmBOooOEiPpb3nJxSeKgZSh4vRGhaNJJ6yC_4KRwQdK6goB1ScBwDkO

[sapote]

Hi,
Yes,
also info on this page which i found out later
https://mlreng.com/blogs/news/e46-m3...dK6goB1ScBwDkO

You meant bolt #16?
I am curious of why the torque on the bolts affects the holding pressure; lower torque causes more internal leak?

[chalaka]

You meant bolt #16?
I am curious of why the torque on the bolts affects the holding pressure; lower torque causes more internal leak?

i believe this is the idea the tech support explained to me.
those 2 small pieces holding the butterfly o-ring and the copper plate together, and copper plate has oil venting directions .. so i think if didn't torque to spec (tight enough), it might cause pressure lost ..as those little gear keep driven by motor to build pressure, and somehow keep losing pressure?