ZF 8HP fluid change - overfill by 0.5L for transmission cooler?

omar.ahmad0524 · 02-16-2023, 06:54 PM

Wondering if anyone who replaced their ZF 8HP transmission fluid followed the step where you overfill with 0.5L of fluid if transmission oil cooler is present.

I believe in the F22 m240i there is a transmission oil cooler present, correct me if I am wrong. I'm going to tackle this service soon and this wasn't clear to me on my research online.

The ZF manual clearly states to overfill by 0.5L if transmission cooler is present, which on the F22 M240i is, but I don't see any videos or DIY guides which follow that step or even state it.

And how do you overfill correctly? You initially fill once fluid starts dripping out, then attempt to put another 500ml in? Probably wont be able to get exactly 0.5L in.

c00lbeansdude · 03-25-2024, 06:31 PM

The cooler has a thermal valve that opens around 160F. So you top off the car around 45C or 112F. Then drive it till the temp hits 160 or stalls around there from the cooler opening. Then park and put on jack stands. Wait till cools slightly under 40C or 104F. Then turn it on again and repeat the top off process.

02-16-2023, 06:54 PM	#1
omar.ahmad0524 New Member 3 Rep 19 Posts Drives: 2018 bmw m240xi Join Date: Nov 2022 Location: texas iTrader: (0)	ZF 8HP fluid change - overfill by 0.5L for transmission cooler? Wondering if anyone who replaced their ZF 8HP transmission fluid followed the step where you overfill with 0.5L of fluid if transmission oil cooler is present. I believe in the F22 m240i there is a transmission oil cooler present, correct me if I am wrong. I'm going to tackle this service soon and this wasn't clear to me on my research online. The ZF manual clearly states to overfill by 0.5L if transmission cooler is present, which on the F22 M240i is, but I don't see any videos or DIY guides which follow that step or even state it. And how do you overfill correctly? You initially fill once fluid starts dripping out, then attempt to put another 500ml in? Probably wont be able to get exactly 0.5L in.
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03-25-2024, 06:31 PM	#2
c00lbeansdude New Member 5 Rep 27 Posts Drives: x5 Join Date: Jun 2023 Location: WA iTrader: (0)	The cooler has a thermal valve that opens around 160F. So you top off the car around 45C or 112F. Then drive it till the temp hits 160 or stalls around there from the cooler opening. Then park and put on jack stands. Wait till cools slightly under 40C or 104F. Then turn it on again and repeat the top off process.
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