My 1999 IH 4900 leaks rain water into the cab. It comes in above the fuse box and puddles on the drivers side floor. I recently had the cracked windshield replaced and hoped that would solve the issue but it made no difference at all. There are no outside visors, air horns or other external attachments other than the standard cab lights above the windshield. Any ideas out there?

I would try the gaskets behind the chicken lights. I had a few 4700's in my dads towing fleet that would leak due to the housings being removed too many times. I would replace those first since they are cheap and easy, after that you are going to be looking into getting that window resealed or a heater core seal.

If the heater core seal is no good, water can pool in the HVAC box and come through the cab also. There should be a drain that gets clogged with debris. The drain should be engine side of the firewall IIRC or comes down and out the passenger floorboard.


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Was the windshield gasket replaced too? I had a new windshield put in my '93 4900 and the old gasket still leaked. Ended up freezing where it puddled up up in the bottom of the gasket track and cracked my new window. Had him use some of the black window caulk in the gasket the next time.

Good call, I didn't think of that.


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You hit it right on the head Horsehaulin! Took awhile cuz I had brake issues to deal with. Waited for the rain today and duct taped the lights on the cab yesterday and after an inch of rain the floor is dry. Normally the floor would be drenched with that much rain. On to new gaskets.
Thanks!

Had to be between Golddigger and my Post. One of those problems was going to be it. Glad it worked out simple. Be safe out there buddy!


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