Bypass hose

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aaronk785

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Why am I blowing bypass hoses. Blown up two in a week. Only thing changed is new belt. Anyone else have this problem. I think belt was slipping before, but this still shouldn't be a problem. Thanks.
 
When you say "blowing" do you mean the hose came apart or came off the nipples
 
Where are you getting the hoses?
What brand?

Even if one end of the bypass hose was completely plugged I would not expect the hose to do that.

Have you checked you rad cap. It might be stuck closed causing excess pressure on the system.

IMHO the water pump would not be able to produce more pressure in the system than a 16 lb cap can. It is only there to circulate the water and while there is some resistance to movement through the engine I doubt it is a lot. (I could be totally wrong)
 
Gates hose at oreillys. Haven't blown a hose in 5 yrs. Rad cap is 16lb. I have a 13 if you think that would help. Never blew any other hose just this one. This is a 68 so it has the old cast iron water pump if that makes any difference.
 
Just for grins and it is cheap. I would get a length of heater hose and use that as a bypass. Make it about a foot or so long, and make a large loop in it from one nipple to the other.

I have a 67, same cast iron wp no issues 4 years. Also gates hose.

Post some photos of the burst hoses.

There might be a bad batch out there OR maybe the auto parts store has had the hoses on the shelf for 40 years?
 
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They do come in two different diameters. Not sure which year uses which. I use to have the smaller one on a Magnum small block and it did blow. The larger diameter has held up and is a lot easier to install.
 
I have sometimes trim back the hose where it fits the manifold nipple, the excessive length will make the bend into a restriction..

bypasselbow.jpg
 
OP; you mighta mentioned that in post #1.
Time for a Cooling System Pressure test, and
a Compression Test, and possibly/probably
a LeakDown test on one or two cylinders. I'd be looking for an unauthorized connection between the cooling system and a chamber, probably/ hopefully, just a head gasket.

But before that;
do not crank the engine with the plugs in! If you are getting water in one cylinder you may bend a rod during cranking.
Pull the plugs out, looking for water, or evidence of water, especially if it has been cranking funny lately.
And check for water in the pan. Let the engine sit overnight, then drain a cupful of "oil" to see what comes out. Once oil gets into a chamber with the valves closed, the only way out is past the rings and into the pan.

I hope I'm wrong
 
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I think it was the cap. It use to have a lot of pressure in the hoses when I turned of the car. Now it has very little pressure in the hoses and no overflow water in the catch can. Both caps are 13lb. caps. No problems so far and many 6500+ shifts. Temp stays at 180.
 
Heres pics of new bump hose(neoprene inside?) Versus an older oem. As diver mentioned trimming and maybe different nipple sizes?
Glad ya got it figured out!

20210323_134739.jpg


20210323_145243.jpg
 
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