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Can a broken vacuum line on the BPT effect automatic transmission?


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I posted two years ago about a 1997 Legacy 2.2 I purchased that had over heating problems. I took it to a bad mechanic to have him replace everything and anything that could cause problems on the road and when he put it back together with the new timing belt he had the timing off and blew the valves. Two years later I finally had enough money to pay someone else to rebuild the heads and put it back together but now the transmission is slipping every now and then and the check engine light comes on showing issues with the EGR system and I quickly noticed a vacuum hose is broken off the BPT (Back Pressure Transducer) and have a used one ordered now.

 

I'm hoping the vacuum issue might be causing my automatic transmission to slip and wonder if anyone knows if it is likely?

 

The kids who put my car back together did overfill the transmission fluid a bit and I am not certain if they put the right fluid in and just how sensitive the level is in regards to slight slipping.

 

Any and all opinions are welcome. TIA

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Since these are electronic controlled, I can't see a vacuum leak causing any type of slip. But that's just my opinion.

 

I do know from experience that they can behave very strange w/o the right amount of fluid. Try a good ol' fashion drain and flush, with the proper fluid. Another thing to look into is if the transmission pan has any type of dent in it. A poor mechanic would use the transmission pan as a way to support the transmission when pulling an engine. Putting even a slight ding in it can block the pump, possibly causing a slip.

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Since these are electronic controlled, I can't see a vacuum leak causing any type of slip. But that's just my opinion.

 

I do know from experience that they can behave very strange w/o the right amount of fluid. Try a good ol' fashion drain and flush, with the proper fluid. Another thing to look into is if the transmission pan has any type of dent in it. A poor mechanic would use the transmission pan as a way to support the transmission when pulling an engine. Putting even a slight ding in it can block the pump, possibly causing a slip.

 

The pump is behind the torque converter; however, a dent or damage to the trans pan could injure the valve body, which can cause poor shifts and slippage.

 

Most Subaru ATs work better slightly under full; they start to have issues when they're overfilled.

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The pump is behind the torque converter; however, a dent or damage to the trans pan could injure the valve body, which can cause poor shifts and slippage.

 

Most Subaru ATs work better slightly under full; they start to have issues when they're overfilled.

 

Yes, my mistake. I should have said "oil pickup tube", not pump.

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My new/used BPT will be here tomorrow. That will allow me to reconnect the one vacuum line that is just flopping in the breeze right now and what I hope is the cause for the EGR code for the check engine light. I'm hoping that will smooth out the idle.

 

I will drain the transmission fluid and add new fluid at the proper level and check the pan for dents.

 

Thanks everyone. Will keep you all posted.

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