PHH

[Wayne]

When doing the PHH replacement, is silicon high temp hose recommended, and what size hose is needed?

 

[Gumby]

5/8 silicone slips right on. It's spendy, but you will have a lot left over from a foot. Others extoll the virtues of Gats green stripe, but it's very still and hard to bend into place.

 

[IdahoDoug]

I used the silicone. Did not use the heat shrink clamps they recommend as replacing these later is a nightmare due to restricted space (you need to cut them off!). I'm using the spring clamps that came on several heater hoses from the factory, but had a slight leak I attributed to one clamp not being fully on the silicone hose (green, from NAPA). I'll know if this was the case when I check for leaks in a few weeks.

Doug

 

[cruiserdan]

I prefer the green Silicone cop car stuff, with lined stainless steel worm drive clamps. The stock spec for the length is 50 mm.


D-

 

[Rich]

If you are really really particular then with silicone hose you will use lined stainless steel worm drive clamps that incorporate a constant tension spring. The spring compensates for the fact that silcone hoses don't bond to the metal pipe the same way that rubber hoses do. The spring helps prevent cold leaks. This is according to web research I did in the past.

I used Gates Green Stripe hose to do the job. In my personal experience of doing the job once, in order for Gates Green Stripe to be a practical choice you should be prepared to fully remove and reinstall the metal coolant pipe that runs from the top of the block down to the PHH. Doing this requires patience, agility, patience, long arms, and patience. If you are in short supply of any of the above, I believe silicone hose is the better choice as I understand it can be more easily installed without removing the pipe.

Rich

 

[Riley]

Oh boy, now I need a course in heater hose materials. They didn't cover this in shop class.

So what color is the "good silicone" hose that I can use without pulling off the pipe?

I hope it's not green or I'll be getting confused with Gates green hose. :-\

I thought changing the hose would be tough enough but now getting the parts is going to take a PHD.

 

[IdahoDoug]

Riley,

Tragically, the NAPA silicone hose is indeed green. To help you keep them straight, the Gates Green Stripe has a green stripe, and the green silicone is - well, green.....

Doug

 

[anderaa13]

If you use silicone, use some type of clamp that keeps constant tension as rich mentioned. I didn't, and have had problems with cold coolant leaks using napa green silicone and regular lined clamps.
aaron

 

[Riley]

Regarding the >> lined and constant tension spring clamps <<

Simon has spent the morning trying to find the above clamp in Western Canada with no luck. He can only find the lined clamps.

We trust that not having the tensioner spring is ok perhaps not considering other previous posts. Maybe we need to continue with more research and get our PHDs before proceeding.

For the record the clamp part number we found is: Tridon ET-10
We think the correct size is 27mm.

This is a lined clamp but has no constant tensioner spring.

I hate to think how much $$ in time and energy was spent trying to find these clamps and the "green" silicon hose (not the Gates green stripe stuff). PHDs don't come cheap.

Living in Canada is like living in a 3rd world country when it comes to finding specialized parts.

 

[cruiserdan]

Well,......the beer's not bad and the hunting's really good

 

[Rich]

[quote author=Riley link=board=2;threadid=7219;start=msg60323#msg60323 date=1068235790]
Regarding the >> lined and constant tension spring clamps <<

Simon has spent the morning trying to find the above clamp in Western Canada with no luck. He can only find the lined clamps.

[/quote]

Look at catalog page 206 at http://www.mcmaster.com/ for an example.

Rich

 

[Riley]

Very cool site. Thanks Rich!

You should take the role of head non-OEM purchasing agent for the 80's forum.
Dan's already got the OEM job.

R

edit - in the new version of the catalog it's on page 211

 

[Wayne]

I really appreciate the tech help on this job.........

Wayne S

 

[landandsea]

My boat diesel mechanic told me he no longer uses silicone hoses. He said they often drip when cold. You might not notice the small amount of initial seepage on a vehicle, but it accumulates under the engine in a boat. Also, there's many more connections to leak on a boat engine - with all the coolers and heat exchangers.

Don't mean to rain (or leak) on anyone's silicone PHH parade, just passing on the experience of someone who has to live with the results on a daily basis.

Ed

 

[cruiserdan]

Ed,

I'm curious. That stuff is all I ever see on cop cars. I have several friends in law enforcement and that does not appear to be an issue for them. I wonder what the difference may be?


D-

PS, you'd think if anything would leak, it'd be a Caprice

 

[landandsea]

Dan,
Perhaps the difference is that it's not their car. They didn't just spend a bunch of their own money and end up with drips.

The durability of the silicone hoses most likely offsets the mostly imperceptable seepage.

Silicone is bullet-proof, isn't it?

Glad to read you're out of inventory hell

Ed

 

[Pitbull]

When mine was replaced it would leak an amount the size of a quarter if it set for 2+ days. If it did not set for over 2 days there was no leak. Pressure tested it and could not get it to leak. Finally installed some Barr's and it quit leaking. Barr's is also suppose to be good for my water pump and they use it in all new GM vehicles on the assembly line so I figured what the heck. That was 9 months ago and no leaks or problems.

 

[landandsea]

[quote author=Pitbull link=board=2;threadid=7219;start=msg60645#msg60645 date=1068314598]
Barr's ...they use it in all new GM vehicles on the assembly line... [/quote]

That could also be interpreted as a lack of confidence in the tolerances of GM parts and in the abilities and training of the assembly workers. ???

Ed

 

[cruiserdan]

Noooooo, couldn't be

 

[landandsea]

I'm sure that neither Toyota nor BMW or Porsche use stop-leak as OEM.

Notice, Cdan, the good company I associate Toyota with.

Ed