Hoses, Clamps & Age - PeachParts Mercedes-Benz Forum

shertex · #1 11-01-2010, 08:17 AM

Just a general inquiry from someone who doesn't have a lot of experience with these things....

When an old rubber hose is loosened, disconnected, and reconnected after a long time of never being disturbed (in my case, probably 20 years), is it usually possible to get a tight fit using the same hose and the clamp on the same part of the hose? Or, since that section of hose has been compressed by the clamp all that time (thereby losing its "spring"), is it often necessary to replace the hose or at least cut off the end to ensure a tight fit?

I just replaced my original auxiliary water pump and it's taken me a few times to get what I THINK is finally a tight fit. But if I'm still losing slight amounts of coolant, do I keep fiddling with it or do I snip or replace the hose?

Thanks.

layback40 · #2 11-01-2010, 08:23 AM

20 year old hose, replace it!!
In an emergency you could put RTV on the fitting before you put the hose on.
if your working on a 60x do you wish to risk a hose failure & a motor overheat for the sake of a bit of rubber hose?

shertex · #3 11-01-2010, 08:32 AM

Quote:

Originally Posted by layback40

20 year old hose, replace it!!
In an emergency you could put RTV on the fitting before you put the hose on.
if your working on a 60x do you wish to risk a hose failure & a motor overheat for the sake of a bit of rubber hose?

Makes sense. Of course, I've already done the job....I'm a bit reluctant to go back in there.

francotirador · #4 11-01-2010, 10:57 AM

Quote:

Originally Posted by shertex

Just a general inquiry from someone who doesn't have a lot of experience with these things....

When an old rubber hose is loosened, disconnected, and reconnected after a long time of never being disturbed (in my case, probably 20 years), is it usually possible to get a tight fit using the same hose and the clamp on the same part of the hose? Or, since that section of hose has been compressed by the clamp all that time (thereby losing its "spring"), is it often necessary to replace the hose or at least cut off the end to ensure a tight fit?

I just replaced my original auxiliary water pump and it's taken me a few times to get what I THINK is finally a tight fit. But if I'm still losing slight amounts of coolant, do I keep fiddling with it or do I snip or replace the hose?

Thanks.

Shoot me if you like, but it's incredulous to me that one would do that job and not put a new hose in. I mean, it shouldn't even be a question.

shertex · #5 11-01-2010, 11:15 AM

Quote:

Originally Posted by francotirador

Shoot me if you like, but it's incredulous to me that one would do that job and not put a new hose in. I mean, it shouldn't even be a question.

Not all of us know as much about auto maintenance as you do...but we are eager to learn. Thus we ask questions that may seem basic to those who are more experienced and are very grateful for the advice we get. (Incidentally, the word is "incredible," not "incredulous;" if you find something incredible then it's the person, not the thing itself, that is incredulous.)

However, it may be of interest that I posed to the question to Rusty at buymbparts and his opinion was that, as long as the hoses are in good shape, it's fine to leave them. So apparently there is some difference of opinion even among those who have significant experience.

vstech · #6 11-01-2010, 11:20 AM

for some odd reason, perhaps it is the temps that these cars operate in, but hoses last an incredible amount of time and remain very usable. especially the ones on the body panels away from the engine, like a aux pump hose would be. new hoses are great, and I try to replace anything I take apart, but many hoses are just impossible to reuse too. if I had something leaking, I would locate the leak and verify it's the hose and not the pump itself. but if the hose is leaking I would not attempt to cut it short. just replace it.

Tpawlik · #7 11-01-2010, 11:56 AM

Until it started to get colder, I didn't even know there was a AWP on my car.

Mine started leaking last week. I thought the housing for the impeller was leaking, turned out to be a loose hose clamp on the outlet side. I took it out and cleaned it and RTVed the housing just in case. I also cleaned the rust and scale off the fitting at the IM and the inside of the hose. To get a better seal I cut off about 1/4" of hose that was soft and re-attached the clamp where the hose was in better shape. I will replace the hose. I just wanted to put the pump back into service.
Now the temperature gauge is a couple of degrees higher when stopped in traffic. Turning on the heat should lower the tempreature. What's up?

vstech · #8 11-01-2010, 12:03 PM

you sealed up a leaking water system. you may have a head gasket problem adding heat to the system that was boiling off before...

Tpawlik · #9 11-01-2010, 12:22 PM

I'm pretty sure the temperature is only higher when the heat is on. I'll check the gauge on the way home tonight. I don't even want to think about cylinder head issues.
Thanks.

francotirador · #10 11-01-2010, 12:25 PM

Quote:

Originally Posted by shertex

Not all of us know as much about auto maintenance as you do...but we are eager to learn. Thus we ask questions that may seem basic to those who are more experienced and are very grateful for the advice we get. (Incidentally, the word is "incredible," not "incredulous;" if you find something incredible then it's the person, not the thing itself, that is incredulous.)

However, it may be of interest that I posed to the question to Rusty at buymbparts and his opinion was that, as long as the hoses are in good shape, it's fine to leave them. So apparently there is some difference of opinion even among those who have significant experience.

I'm no auto repair expert. Far from it. I'm a novice DIY'er. That notwithstanding, I know that if I'm going to do any kind of work on my car I'm going to change rubber parts that are old. I'll do it just because they're there and just because I wouldn't want a failure and have to do the same job again because of it. That's not even mentioning the possibility of getting stranded on the side of the road because of it.

Additionally, hoses often deteriorate from the inside. So, they may look good on the outside, but are near their useful life on the inside.

cirrusman · #11 11-01-2010, 12:32 PM

Heck, now you know, right? You live, you learn...

Biodiesel300TD · #12 11-01-2010, 12:43 PM

Quote:

Originally Posted by francotirador

Additionally, hoses often deteriorate from the inside. So, they may look good on the outside, but are near their useful life on the inside.

This is true, and with coolant hoses generally you can give them a squeeze and if they are really soft and collapse easily it's time for a new hose, but it they are still firm then usually they are okay. Sometimes its a good idea, if you hvae the space, to cut of a little bit of the end, so that you are clamping in a new spot. This will often help with those pesky drips.

The, "while you're in there" parts can add up. But lots of times you don't what to have to pull that part off again or will have to pull a lot of other stuff off to get to it. In general I replace servicable parts, "while I'm in there", if they are cheap, critical, or hard to get to. Sometimes it's expensive, and other times it's less than $1.

Junkman · #13 11-01-2010, 12:57 PM

I'm not really interested in needing a tow because I tried to stretch a few more miles or a year out of a hose. In the cases where I'm too cheap to buy OEM, I'll match something up. Frequently there is a les expensive brand name molded hose that when cut will approximate the curves of OEM. Having a hose spring a leak usually indicates of PPM.

Diesel911 · #14 11-01-2010, 12:58 PM

A Rubber Hose just sitting on a shelf somewhere will lose elasticity after 20+ years.

Everyone has their own way of doing things but I believe what the others were trying to say is that it was the same amount of work do do what you did as it would be if you had installed a new Hose.
The exception is that re-using the old Hose means you will be doing the job again sooner than you would if the Hose was new.

t walgamuth · #15 11-01-2010, 01:08 PM

My experience is that the factory hoses on a benz seem to be about indestructable. I am doubtful of replacing them with hoses that may not last as along as the old ones that are still there from the factory.

I don't generally replace them unless there is a clear and obvious problem with them.