Perfect silicone bypass hose for water pump
 

Today I got stuck doing my water pump.......again. :icon_slap: I wish I had taken pictures, but I was so stressed and pressed for time getting everything done before work, that I plain old forgot. :icon_hyper:

In case you did not know, there is a rubber hose that runs out of the top of the water pump, and under the accessory bracket. In order to change out this hose, you basically have to get down to the point of removing the water pump, because the hose is jammed pretty good between the 2 fittings it connects to. Long story made short, you do NOT want to have this fail on you. This will be one hell of an operation that you will have to pull off to get your van running again.

When I first saw the hose, the first thing I thought of was a silicone radiator hose a friend of mine had as a spare from his Honda Civic. Low and behold, it was a perfect fit. The bend in the silicone hose was the perfect angle, internal diameter perfect, and all I had to do to make it fit was to cut a few inches off of each end. This is a much better idea than using what the parts stores will give you; a universal straight rubber hose that not only has to be cut to length anyway, but will kink badly when installed.

The idea here is that silicone hoses are alot more durable than rubber hoses. Police/Civil Service package vehicles have been using silicone hoses for some time, and they work.

The hose I got was from a 1995 Honda Civic. Mine was a Skunk2 hose, but you can get aftermarket silicone hoses from a wide range of aftermarket companies.

As far as the rest of it goes, I chose the new Bosch water pump that Pep Boys carries after reading alot of seriously bad reviews on the GMB pumps that Advanced carries. Autozone has their Duralast pump, but for the same money, I would rather have Bosch. Coolant fill was Zerex G-05.

Interesting. LA engines must have different bypass hoses, which makes sense cause the water pumps spin opposite directions.

My Bypass hose came with a bend in it, but I still wound up cutting some off each side to keep it from kinking/creasing.

The hose I had previous to this was weeping from the bend where it had creased and was only a few years old.

I remember that hose very well when I removed my intake to replace the intake and plenum gaskets. I looked at it and said to myself that there was no way I was going to reinstall the intake without replacing that hose. It was so easy to do with the intake off that I would've been certifiably insane not to replace it at the time.

Then besides just replacing it, I also inserted a restriction to close the ID down to a 1/2". I did this to help with the heater output during the winter months. The one problem with this hose is that the ID is 3/4" and that allows too much coolant to bypass the heater core. By inserting the restriction, more coolant is forced through the heater core, which in turn raised the air temperature coming out of the vent by about 10 degrees. That 10 degrees made a huge difference the following winter.

Good advice. If I ever find myself in there again, I will certainly do that.

Was just out for drive, and even with AC on full blast, I never saw more than 140 degrees during the whole trip. I verified this by opening the radiator cap and sticking my finger into the coolant. It would have made for a nice bath. I punched a couple of small holes in the thermostat to stop it from trapping air. I wonder if that might be bypassing enough coolant to keep temps from getting up to thermostat rating (195), because usually, I see almost 200, or maybe slightly more, even only a short time into a short trip.

Also, I did replace that coolant temp sensor below the alternator, as per the advice of a member here. ;)

Van seems happy now. Let's hope things stay that way.

I have always been able to buy the hose with the slight bend in it. But I have found that cutting a little bit off each end helped in installing and keeping it from kinking.

Alloro how did you restrict the bypast hose? sounds like I have to do the same thing on my motor. My truck is cold during the winter. 5.2L motor.

I inserted a nylon bushing inside the bypass hose that was 3/4" OD and 1/2" ID.

If you go to the gates website the maker of silicone and normal hoses there is an article on hose selection.
Silicone is best used in a high temperature situation and is NOT recommended for normal radiator hose use BECAUSE the silicone does not self seal to hose fittings and will be a weeper and leaker unless you use special constant tension hose clamps.

Alloro, thanks for the information. I'm changing my water pump this weekend. I'll try to find a nylon bushing at Home Depot. The by past hose looks like it has an ID of 15/16"