I was looking online earlier today at hose kits for the XJS. Looks like there are about a total of 15 hoses involved for the radiator/cooling + heater systems.
One thing I found interesting is that one vendor (here in the U.S.) sells their kit using hoses made out of the usual stuff (i.e. rubber?). Another vendor (in China, FWIW) sells for about 1/3 less $$ a similar kit, but all the hoses in it are made out of āwipeableā, shiny silicon. This vendor claims that the use of silicon makes the hoses impregnable to sunlight, oxidation, U.V. rays, chemicals, acid, corrosion, heat (up to 260 degrees, IIRC), etc. etc.
Wondering what everyoneās thoughts are on going with the silicon variety, and would there be any potential pitfalls to using them?
Havenāt tried any silicone hoses in years. Back thenā15-18 years agoā some of the silicone hoses were high grade (and expensive) while others were very junky.
I mustāve decided the cost-benefit ratio didnāt work for me so I havenāt even considered using them in a long time.
I donāt have recent experience to guide you to āthe good onesā, but be careful!
In my opinion you should stick with the original style rubber hoses. The kits supplied by the regulars are good.
Do not use Kevlar . Donāt ask me how I know.
Just make sure that when you install them you have them fully inserted, This is particularly important for the lower rad hose. Rubber lubricant helps position them.
Bob
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
4
Ooooh, I gotta ask! I presume Kevlar would be in the fiber reinforcement within the casing of the hose, and would make the hose tough so it couldnāt possibly blow out under pressure. Are there multiple companies offering such, or just one? And do you believe your negative experience is due to shortcomings of that particular manufacture, or is it an inherent problem with using Kevlar in the casing of a hose?
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
5
Do silicone hoses likewise have fiber reinforcement in the casing?
As far as I could see, they had Kevlar fiber in them, like concrete gets reinforcing fiber: a small bit, mixed in with the rubber.
The Kevlar hose kit was a colossal waste of money. They all degraded within a year. Replaced then with Gates, and they were still in perfect shape, 6 years on.
I only use silicone hoses for airā¦vacuum lines and turbo intakesā¦they hold up to heat much better. For vacuum lines, you can use a simple zip tie to secure them.
Silicone does not do well with oils, and I always was skeptical using it for coolant. If the silicone gets soft, it can collapse. Quality rubber is fine for coolant, IMO.
Gregmatic, where do you get those for the air and vacuum lines (for our XJSes)? I was wondering if anyone makes a hose kit for those systems as well, but couldnāt find any.
The Kevlar hoses did not have any reinforcement that I can remember.
They were very rigid and did not bend nor nor flex easily. It made connections very difficult.
I ran them for about a year and they visually showed no faults.
Eventually the upper rad hose simply tore opened resulting in a two inch rip.
I donāt know who the manufacturer was.
Bottom line ā¦ donāt kill your car with kindness ā stay stock.
Bob
1 Like
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
11
Stress on the upper rad hose increases greatly if the radiator gets plugged up. Still, I would think the whole point of having Kevlar in the hose would be to prevent such failures, so if it fails like this anyway might as well just get regular hoses.
I became aware of silicone hoses in the 80s-90s. Mustang and Camaro guys became aware that cars built with the āPolice Equipmentā package had silicone hoses. Very high grade stuff and very expensive. Somehow the idea caught onā¦upgrade fever, it seemsā¦ and became the rage. Opportunistic manufacturers saw a market for low priced (and low grade) alternatives.
Cheers
DD
1 Like
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
14
As I understand it, āKevlarā - otherwise known as Aramid - is a fiber. If thereās no fiber in the $#%% hose, what the hell is Kevlar about it?
In the car hobby, for as long as I can remember, thereās been a love affair with ālatest and greatestā upgrades and improvements, boutique products, and so forth. Car guys love lavishing their cars with money without a lot of thought to the actual real world benefits. Lots of upgrading just for the sake of upgrading.
This isnāt a criticism, nor me being holier than thou. Iāve been there and done that, believe me . But as the decades rolled on I became increasingly aware that a lot of the time, money, and effort spent on latest and greatest products and upgrades made ME feel really goodā¦but the CAR didnāt give a ratās ass one way or the other. Iāve saved a lot of money, time, and effort as a result.
Oh, I still enjoy upgrades and improvements. Especially those that provide tangible benefits and/or cure actual problems and design flaws. Itās just that Iām more selective than I was years ago.
I used some silicone hoses for other cars, but not for the Jag
The silicone version (if available and properly made) should stand higher temps, so should stay flexible longer than rubber cooked in the engine bay
the hoses I got were made in UK, not China, and the price difference can be great
but such hoses need good clips, as theyāre stiffer, so more difficult to compress on the pipes
and usually fail in catastrophic way : no slow drip but long splits
as noted by Greg, Silicone is NOT for fuel, and Iād be careful with oil, but coolant is fine, as air
the great benefit of the kit is that you donāt have to figure out which hose to order, and can start the job of replacing all at once
The ākitā form is only available for the 5.3L V12, not the 6.0L
. But as the decades rolled on I became increasingly aware that a lot of the time, money, and effort spent on latest and greatest products and upgrades made ME feel really goodā¦but the CAR didnāt give a ratās ass one way or the other. Iāve saved a lot of money, time, and effort as a result.