How to get Silicone Radiator Hoses to Seal?

[Bartonmd]

So I finally got around to putting on my Jetttstream radiator hoses, when I did the 100k maint. a couple weeks ago. The upper hose was really hard to get on (to the point that I lubricated it with some coolant), and it seals just fine on both ends with the stock spring clamp. The lower hose went on with what I would consider a normal amount of effort, and was clean and dry in and out, on both ends. Both ends of the lower hose seep a little with the stock spring clamps, so I moved them all the way to the ends and put a regular worm clamp as tight as I dare, right next to the rib, and they still seep. This is maybe 5-10 drops per trip, I guess. I haven't noticed any movement in the coolant level in the burp bottle or radiator, so it's not a horrible leak, but it is leaking. I know that silicone hoses don't vulcanize to the contours and "print" of the mating surface, so I suspect this may be what it is, but how do I fix it? Do I use those T-bolt clamps like on turbo piping to get it extra tight (without crushing the pipe, hopefully), and/or rub some RTV around both male fittings, then slide the hose over and clamp it?

I know several people run these, so I'm curious as to how you got yours to seal?

Thanks,
Mike

 

[The_Roadie]

Never put them on, and then lost them in the garage for a year. Just found them again, and was going to put them on soon.

 

[Bartonmd]

Man, that sucks. You were the one person that I knew had them, though we got them the same time, and I just got around to installing mine, so... yeah...

Anybody else with any experience with silicone radiator hoses?

Mike

 

[DFWWIZ]

Man, that sucks. You were the one person that I knew had them, though we got them the same time, and I just got around to installing mine, so... yeah...

Anybody else with any experience with silicone radiator hoses?

Mike

I got them from TBSS Nats and put them on with no problems using same clamps.

 

[jimmyjam]

never had an issue with mine, use worm drive clamps...

 

[Wooluf1952]

I also bought mine from Jetttstream. It took me at least a half hour to get it in the t-stat neck. I finally hat to remove the t-stat and put it in a vice to get the leverage, along with some slippery Dex-cool, to get the hose on.
For clamps, I used the special ones designed to keep from cutting into the hose.
I haven't had any leaks. However I do check and tighten the clamps whenever I have the hood up, the engine is hot and remember to.
On a side note, the t-stat I used was a Stant. The hose was a lot easier to slide in the AC t-stat that I removed.

 

[Bartonmd]

From the searching I've been doing on the net, it would seem that the silicone hoses are prone to seeping, without tighter-than-stock clamps. I ordered some T-clamps that'll be here in a couple days. I think I'm going to take it apart next weekend, clean/dry everything out/off, put a film of RTV on both males (mainly to smooth out the "grain" of both male ends that the hose goes onto), put the hose back on, tighten with T-clamps, wait 24 hours, then re-fill the coolant.

Thanks,
Mike

 

[Sparky]

What's the benefit of those silicone hoses vs standard hoses?

 

[Bartonmd]

What's the benefit of those silicone hoses vs standard hoses?

Better long term pressure and temperature resistance. As an example, if you buy a 1991 Caprice cop car that had the silicone hoses from the factory, they are likely still in good shape, and are considered better than the replacement rubber hoses you buy, even now.

Mike

 

[ByCo]

I don't have any first hand experiance with the silicone hoses but when I was selling parts back in the nineties the silicone hoses were introduced for the heavy duty truck market. Gates Rubber Co. had a special heat shrink clamp that they recommended for use with the silicone hoses because of leak problems when using standard hose clamps.

 

[ScarabEpic22]

I installed my Jetttstream hoses last month on my SS, I used lined work clamps (have an extra part so the worm area of the clamp never contacts the hose). Either those or t-bolt clamps are the way to go, fwiw I havent had any leaks.

 

[Bartonmd]

Well, I figured out why they were weeping. See the picture below. There are imprefections on the insides of the ends. They aren't very deep, and I'm sure that a rubber hose wouldn't care about them, but this one did.

I haven't gotten any reply from Jetttstream since I emailed them the morning that I started this thread, so I don't even know if they're still in business, so I put a coating of RTV around the male connections that these to onto, put the hoses on, tightened the T-clamps, and am leaving it for a couple days before I put coolant in it. We shal see.

 

[ScarabEpic22]

Interesting, I didnt notice that on mine (but again I didnt look either).

Heads up, Mike at Jetttstream is out of the TBSS world completely, I havent heard/seen him in a year plus.

 

[Bartonmd]

Like I say, mine are probably 3 years old, so they likely aren't the same batch.

Yeah, I suspected as much. I hadn't seen/heard anything from him on any forum in quite a while, either.

I'll fill this up tonight, and see how it does.

Mike

 

[ScarabEpic22]

Like I say, mine are probably 3 years old, so they likely aren't the same batch.

Yeah, I suspected as much. I hadn't seen/heard anything from him on any forum in quite a while, either.

I'll fill this up tonight, and see how it does.

Mike

Ha I dont know man, I bought mine in 2009/2010 and FINALLY installed them this past December. They could be the same batch, no idea.

 

[The_Roadie]

I think there was only ONE batch. I got one of the first sets, and at the very end, they hadn't all sold so he dumped them cheaply and I pushed them on ORTB. Classic case study of people claiming there's a market for a product, a vendor invests in the tooling or minimum buy quantity to have them in stock, and then people decide they're too cheap-ass to pay for a superior product. I'd be surprised if I hadn't seen it dozens of times.

 

[jimmyjam]

one run of the I6 hoses maybe but plenty of v8 hoses were sold

 

[ScarabEpic22]

one run of the I6 hoses maybe but plenty of v8 hoses were sold

Yep, this. Mike made a ton of V8 hoses but only 1 set of I6 ones. I have 1/20 and I think Bill does too.

 

[The_Roadie]

We I6 owners are (by definition) cheaper-ass than the V8 (and especially SS) owners. :wootwoot:

We need the money to fix all the stuff we break offroad.

 

[Bartonmd]

OK, I'm ordering a new AC Delco hose, tomorrow.

I cleaned everything with brake cleaner, put RTV on things, then let it cure for 2 days, before re-filling it.. It's leaking less than it was, but I think that's because the new hose clamps bind it up much tighter. It's maybe 3-4 drops per trip, but it's leaking. Where I'm seeing coolant start to dot out from is the reinforcement webbing, so I think there's a pin-hole in the inner layer that's letting coolant through to the first fiber plies, and slowly out the ends of the hose.

Mike