91 740 leaks when it rains in the interior under the dash

hairyg · Post by **hairyg** » 26 May 2008, 06:45

Hello. I have a 91 740 sedan that leaks through the slots of the brake and gas pedals underneath the driver's side of the interior under the dashboard. How can I get to the leak and where do you suppose it is coming from? It has 78k miles on it.

Thank you very much!

hairyg

Post by **billofdurham** » 26 May 2008, 12:34

Welcome to Matthew's Volvo Site.

Are you sure that there are slots for the pedals? It seems more likely that the water is coming through higher up and finding its way down to the level of the pedals.

One place I had trouble on my 740 was a blocked drain hose coming out of the heater air intake. Air, and water, go through the grille just in front of the windscreen. The air is necessary for the heater, the water is not. On the engine bulkhead (firewall), usually low down, there should be a drain hose which gets rid of the water. Over the years this can become blocked with dirt, leaves and other rubbish. It is easy to remove and clean.

Other points of water ingress are around the sunroof, again blocked drain tubes, and the windscreen if the seal is failing.

Bill.

hairyg · Post by **hairyg** » 01 Jun 2008, 05:17

Bill,

Thanks for the reply. The seal on the windscreen is good. I do not have a sunroof. The water is coming through the brake pedal slot in the interior. Only this side of the car floor gets wet, not the passenger side. I don't see it when it is happening, however, I can clearly see white and light blue water residue on the rubber of the slot.

I checked the tube on the firewall and the tube itself is clear. Could there be a problem or clog up through the opening where the tube gets inserted? How would this get unclogged if it is?

I really appreciate all of your advice and help!

Gerald

Post by **billofdurham** » 01 Jun 2008, 11:47

white and light blue water residue

The light blue water residue is intriguing. It would indicate some sort of additive in the water, possibly anti-freeze. Are you losing coolant?

To check if the whole water drain is clear pour about a quart of water through the intake grille and see how long it takes to come out the bottom of the tube. If it comes out quickly then it is clear. If it seems to take a long time then the top end could be blocked. Remove the rubber pipe and clean out the hole with a metal rod.

Bill.