98 S70 Red TCV Line

[mecheng]

I've finally decided to replace my TCV vacuum hoses. I did the Blue and Yellow. I'm using Dayco Canada hose size 7/32" which is 5.5mm and very stout. I measured the stock hose ID as 6mm but it is much thinner walled compared to the Dayco hose I am using.

I noticed the CBV has a hose, so I might as well replace that one too?

The Red hose from the TCV to the turbo is left, can this one be accessed from under the car? Any words of wisdom or advice? I noticed that if I pre-lub the hoses, I can just pull on them even with the clip on and they come off.

Hopefully, my car will run long enough that I can get it on the ramps. I have the whole air box removed, MAF, etc. If I remember correctly, I remember seeing this hose in some awful hell zone when I was last under the car.
Thanks

[scot850]

Having done this twice in the last 2 months it is truly a bugger! As I only have AWD turbos, it is impossible to attach from below. I removed the airbox, the turbo input plastic tube from the airbox to give ne access. I then spent many happy hours *using a lot of engineering terms and questioning the parentage of the designers.

I was able to access the clip from below to turn it so I could reach it with long nosed pliers while reaching in from the LH side of the engine. Replacing, I fitted the clip onto the pipe about 1" from the pipe end, used a small amount of silicon oil, and slid the pipe all the way on. Tight for room with shovel hands, but got there. Then using a variety of long nosed pliers, managed to get the clip on.

Take time, and walk away if you get frustrated (I do need to listen to my own advise on this!!).

Neil.

[mecheng]

So you attached it from on top? I can't see it end on top. Did you remove the heat shield?

[scot850]

Did not remove the heat shield on either car. The 2000 V70R does not have the same shield as the 98 V70XC. But assuming the 98 XC is the same, still didn't remove it. I did use an extending mirror and torch to help me visualise what I was trying to get to.

Neil.

[mecheng]

Got it done, took me all of 20min, I was surprised. It looked harder than it actually was

I removed it by prying on the hose with a heavy duty screw driver under the car. It was soaked in oil so it slipped right off. Putting it on was tricky but with 5.5mm hose is slipped right on and I used a screw clamp.
Basically avoid using a pliers and this job is easy, there is no room. Use a screwdriver only

Time for beer, got all 4 hoses done, 2 were in bad shape

[scot850]

Well whatever works! Funnily enough, I thought it would be a real pain and it was, but it could have been worse, you could have had AWD!

Glad it all went well. Job well worth doing!

Neil.

[mecheng]

Well whatever works! Funnily enough, I thought it would be a real pain and it was, but it could have been worse, you could have had AWD!

Glad it all went well. Job well worth doing!

Neil.

I'm sure the AWD is tough! It looked tough because the hose is far from reach; the saving grace is that it wasn't fused to the nipple like the other hoses which I had to use a pliers to remove. The oil that is released from all Volvo turbos came in handy LOL!

FYI: The Volvo vacuum hose is 2mm wall thickness, I used 3mm so I never have to worry about this again. Even though two of my hoses were in rough shape, I"m not sure if they were actually leaking. No real performance gain to be honest.

Also, the line from the intake manifold to the CBV has a smaller ID, about 4mm. I still used the 5.5mm line with a clamp.

[erikv11]

FWIW: I used 4 mm for all of the vac lines mentioned here, it works great too.

[mecheng]

You can use 4mm to 6mm TCV hoses. Volvo uses 6mm from what I measured. For ease of assembly I would recommend the biggest you can get in that range. To further ease assembly, put the hose end on one of the TCV nipples for 5 min to let it relax before you try installing it at one of the hard to access sites and spray the hose with silicone lube.

[erikv11]

Always feels good to throw out that crumbling rubber, nice!