How many hoses and What about the flange

[DashingDaryl]

I had the upper hose blow on my 2003 2.5. I have not had the car that long, so I do not know how old it is. I am going to replace it, and the lower, but I see there is also a third hose called a "Cooling-Overflow Hose Water Hose." #4 in the picture

Is that another rubber hose, or is it a hard plastic hose? Does it need to be replaced?

Do you know if they make an aftermarket for that hose? At $88.76, I would like to explore all my options.


Since my car is 20 years old, should I also change the plastic flanges? DO they ever wear out? Afterall, why pay for the coolant, more than once?


Lastly, is there any special burping method I need to follow. I notice there is a bleeder valve in the upper hose, so it seems pretty straightforward.

 

[bigwinn]

Has the hose failed or the o rings in the sealing part? That’s what usually fails?

 

[DashingDaryl]

The upper hose failed. It separated at the factory hose clamp

 

[bigwinn]

Ah yes I’ve seen a few starting to get perished there

 

[enuff_zed]

Ah yes I’ve seen a few starting to get perished there

Funnily enough, that’s exactly why I’m waiting for a hose delivery for wifey’s car.

 

[DashingDaryl]

Funnily enough, that’s exactly why I’m waiting for a hose delivery for wifey’s car.

Nice to know I am not alone in this.

Are you going to replace them all?

I bought the upper and lower already.

Did you buy the third hose?

 

[enuff_zed]

Funnily enough, that’s exactly why I’m waiting for a hose delivery for wifey’s car.

Nice to know I am not alone in this.

Are you going to replace them all?

I bought the upper and lower already.

Did you buy the third hose?

Just changing the top one tbh

 

[colb]

Those factory crimp fasteners are awful, far better with some good quality Jubilee Clips. Power steering pipes on z3's go bad at the pump end where they rot away at the end and under the crimp fasteners. Age related is the usual cause of the hoses failing, plastic stubs do go brittle so take care installing new hoses, apply some silicon to the hose ends or O rings if they have those connections to let them slip on without damage.
When bleeding get the front of the car as high as possible and use the bleeder screw until no air bubbles come out.

 

[DashingDaryl]

Thanks for the tips Colb!

 

[Joez4]

If you do replace the hoses don't buy Gates branded ones, even though they were correct part numbers they did not fit my car. The lower hose needed to be bent to fit and as a result i think will restrict coolant flow and the top one rubs on the crossmember.

If anyone knows a make that does fit then please feel free to reply.

 

[enuff_zed]

Well I’ve always bought Gates with no issues. That’s odd?

 

[Joez4]

I'm not having much luck recently with parts not fitting,

They are good quality hoses but they are not exactly to the dimensions of the originals as a result I've stuck the original ones back on the car

 

[enuff_zed]

I have just received and fitted a genuine Gates top hose. Perfect fit with no rubbing or kinks anywhere.
The seal on the thermostat housing end of the old one had gone flat, allowing the pipe to move and coolant to leak out.
Whole job took less than 20 minutes, including getting the top cover off, bleeding etc.