radiator hose

[Tritium007]

Just got a leak in the upper (fairly new) radiator hose and don't like the way it appears to have happened. Easy fix to replace the hose, but looks like it was caused by the alternator belt rubbing through it. Can someone explain what the proper clearance is for this hose and the fan on the front side and the belt on the rear side? I thought about braided protection for the hose, but that just leads to more belts. This happened following a wonderful cruise of about 200 miles on Saturday, combined backroads and interstate. A picture is worth a thousand words. I do have an issue from the previous owner who had the water pump replaced and therefore the belts are slightly misalligned. They are slightly farther forward than normal at the pump and angle back just a bit to the alternator. Any help would be appreciated.

Thanks,
Mike

 

[cheeseral]

Mine has a guard on the alt bracket to keep the hose away from the belt.

 

[Tritium007]

I have tha guard as well, but the hose still got cut as it doesn't run over the guard. I have since picked up a new hose and it came with a plastic piece wrapped around the hose about where it goes over the belt. I also noticed that the new hose is formed with a more exagerated curve over the top across the belt. It's possible that the old hose was not the correct one or was cut improperly at installation. It had been replaced before I bought the car. At idle, the hose and belt weren't making any kind of contact. Is it possible that there is a bad motor mount causing excessive engine flex at high rpm's that causes the belt and hose to come in contact? I would think there would be other problems associated with that as well. The new hose looks like it will provide a good deal more clearance.

Thanks,
Mike

 

[Nut]

The exact factory hose properly installed should not come in contact with the belt. This also means the belt must be correctly tightened to minimize the movement especially under hard accelleration.

nut

 

[Tom Bryant]

I'm wondering why your belt would be angling back to the alternator. It could be that the shop that replaced your water pump put on a long pump. Most Small blocks in other Chevys after 1969 used the long pump. Corvette stayed with the short pump. The difference is in the legs where they bolt to the block. It should look like the attached photo. If the legs look longer you have the wrong water pump and that will lead to premature belt failure, belt throwing and premature water pump and accessory bearing failure. Your belts should run straight or there is something wrong.

The picture of the '81 shows the correct top hose (original GM part and this is where they lie from the factory) and the belt shield in the proper position. The shield is actually more of a guide that does not allow the belt to rise up high enough to contact the hose under centrifugal force (high rpm). If the pump is the long one the belt may be missing the guide and rubbing on the hose. This all depends on the belt being the right one and the tension being correct as well as the clearance between the guide and the belt being correct.

I couldn't get a good shot of the pump so here is one of my truck engine on the stand also with a short pump. If the legs of your pump are longer and hold the pump further from the block it is the wrong pump.

Tom

p.s. The back cover of the water pump is almost touching the timing cover on a short pump. In the truck engine picture it actually did touch the cover with that custom chrome one on there. I had to relieve some of the pump cover lip for clearance. If you have plenty of clearance, like a 1/4 inch or more, you probably have the long (wrong) pump on there. Sorry. I don't have a long pump for a picture to compare.