Coolant bypass nipple

[fisher]

The water pump is toast and I destroyed the slotted bypass nipple trying to remove it from pump. I've searched for new original slotted nipple but found only 2 suppliers making repro nipples for older BBC. My question is; should I go with a different style bypass nipple?

2000 k2500 ccsb L29

 

[454cid]

I've got a brass industrial fitting on my water pump. The only ones I've found that have the screw driver slot and no hex, are hot-rod/racing stainless steel parts. I didn't want to spend that kind of money at the time.

I wonder if a new water pump would come with a fitting.

 

[fisher]

I've got a brass industrial fitting on my water pump. The only ones I've found that have the screw driver slot and no hex, are hot-rod/racing stainless steel parts. I didn't want to spend that kind of money at the time.

I wonder if a new water pump would come with a fitting.

Sounds like a fitting similar in dimension as the slotted one is ok as long as you can get a good seal with a hose clamp. None of the pumps that I've found locally or on Rockauto or Amazon include the bypass nipple. It's one of those parts that gets reused when replacing the pump. I've read on some forums that it's ok to plug the bypass ports on the pump and intake, and drill a couple small holes in the thermostat to function as the bypass until the thermostat opens.

 

[454cid]

I've read on some forums that it's ok to plug the bypass ports on the pump and intake, and drill a couple small holes in the thermostat to function as the bypass until the thermostat opens.

I would not recommend doing that. There's no way a little hole is going to flow as much coolant as a piece of heater hose. The BBC has used a dedicated bypass since the beginning.

This isn't a hard problem to fix. It's a 1/2" NPT thread with a 3/4" hose barb (or maybe 5/8"?) I think it's 3/4", Though. I got mine from Fastenal, but Home Depot probably has something, too. Even the parts store should have something, it just won't be like the original. I use a short piece of bulk heater hose. I don't like the pre-formed bypass hoses, as they never really fit well, in my opinion.

 

[fisher]

I would not recommend doing that. There's no way a little hole is going to flow as much coolant as a piece of heater hose. The BBC has used a dedicated bypass since the beginning.

This isn't a hard problem to fix. It's a 1/2" NPT thread with a 3/4" hose barb (or maybe 5/8"?) I think it's 3/4", Though. I got mine from Fastenal, but Home Depot probably has something, too. Even the parts store should have something, it just won't be like the original. I use a short piece is bulk heater hose. I don't like the pre-formed bypass hoses, as they never really fit well, in my opinion.

I did the same when I replaced the bypass hose. I'm going to find a hose barb like you mention. Just waiting for my new pump to get delivered and then button everything back together. Thanks for your feedback.

 

[someotherguy]

Dorman has a selection of these fittings at pretty much any auto parts store. No slots but you don't need them, unless you're going for a museum-quality restoration or something.

Example https://www.dormanproducts.com/p-11844-56360.aspx?origin=keyword

Richard