roxynoodle

I just looked at the check valve for my IWEs as I bought my truck used and wasn't sure if it had been replaced. I'm still not 100% sure as mine doesn't have the one blue end. Instead it has a dot of blue paint about that color on it and a drip of that paint underneath it.

However it has the same tag and part number (FL34 7A788AC) as this one on ebay that's supposed to be the replacement part. Does that mean it's been done? The check valve and solenoid both look almost new and a newer than the other parts.

https://www.ebay.com/itm/25484630417...Bk9SR-7buuDbYQ

johnday in BFE

iTrader: (1)

IIRC, the 2018 should have come with the updated valve. They aren't very expensive, and many of us carry a spare in the glove box. You can also substitute a YG360 checkvalve for the OEM, those are available at parts stores.
Are you having problems, or just looking around?

roxynoodle

No problems. I just read a thread the other day about someone who bought a new used truck and other people told him to replace it if it hasn't been done and I've read numerous other threads about the problem so thought I should check it.

Mustang71

The latest service bulletin they say to unhooked the vacuum hose from the ice solenoid and plug the hose

mbrick

Yes, but I (and I think many others) would rather replace the check valve and diagnose a leak than do this.

David Hineline

That is only for 4A optioned trucks, the original poster listed a base XL, and 2018s manuf. in early fall 2017 did not have the new check valve or the tccm update so the IWEs don't get vacuum until driven 1/2 mile.

roxynoodle

Thanks for that info!

Yes, base XL so no 4A. It was manufactured in February 2018 and I bought it in September 2022 and am the second owner.

Is it worth having a spare check valve on hand? Solenoid too or just check valve?

babock

I keep some spares on hand


I will never just disconnect...I want the IWEs to do what they are designed to do.
I am replacing these once a year...they are cheap.

2008__XL

a I have a 2017 so not the new style. Out of curiosity, what is the issue when the IWE’s don’t have vacuum until half a mile? The new blue check valve corrects this?

Ive never had an issue, but I’m going to replace this part as it’s cheap and easy.

johnday in BFE

iTrader: (1)

I'd say it's more of a feature. The programming for that is controlled by the TCCM. It's supposed to prevent the IWEs from grinding, and supposedly warm the front diff.
The newer checkvalve appears to be a different compound on the flapper and seat. It seems to help with colder temp operation. They still sometimes fail.