Primary CVT unit failure

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jtbo
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Primary CVT unit failure

Post by jtbo » 05 Jul 2013 11:08 am

After doing some testing and observations I have concluded that my 343 has failure at primary CVT unit, pulleys are not moving and remain at low speed position.

It is quite challenging to do blow tests as can't find hose that would be perfect fit, but compared to other side I think that there is no pressure buildup when doing tests and I can keep blowing.

One thing I found out was that idle speed changes quite a bit when using low gear switch now that I did seal carb leaks, before there was not much difference.

I could not spot any movement at front pulleys, no matter how I did accelerate, used low speed switch etc. and as my best attempts at blow test seem to be failure, then perhaps there is no way around the fact that I need to repair primary cvt unit.

What kind of work I'm looking in here?
I'm not quite sure if I can do the job or even swap another unit, so I would like to find out before hand a bit of things needed and overall task if I should attempt it or not, car that moves by itself is still better than one that is at pieces.

I need still to triple check blowing to other hose, but I do recall from previous testing that it did behave much better, too hot to attempt work at the moment though, so I thought I start preparation to worst.

Yeah, fail car, or is it just me? :lol:

Edit: I did read again mac's article about CVT, I had forgotten already few things in very short time, which is new normal, anyway I find there is still chance of failure being in hose instead of unit itself, which at least sounds like being easier fix, if that is the issue, need to lift also front of the car up and then rear much higher so that I fit under the car and can attempt to find those hoses, perhaps I take that overdrive side that seems leaking out and block EMV side, then blow from under the car to hose if that would reveal leak in hose itself, then I could be certain which bit is faulty really.

Not sure if hose failures are common or typical or what are typical issues, but better check all things possible while motivation burst lasts.
Volvo 360GL -88 -under restoration-
Volvo 343DL vario -81 -running- Image
Volvo 240 Diesel -83 -undecided-
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jtbo
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Re: Primary CVT unit failure

Post by jtbo » 05 Jul 2013 02:37 pm

After removing all CVT plastic covers, I found out that one hose had came loose at front side of primary unit, not sure if that has been loose before or has it came loose recently.

I did test both sides of primary unit and they worked fine, when blowing, connected all hoses, tested from engine bay and both test ok, however smaller hose is such that pressure slowly disappears, it does blow back, but it is not like bigger side which would hold air forever or at least almost, not sure if that is considered a fail or pass, it is very very tiny amount that one need to add air constantly and it does blow back very well.

Then new failure came, which I wrote to fail car topic, of course fix one another gets broken sm1
Volvo 360GL -88 -under restoration-
Volvo 343DL vario -81 -running- Image
Volvo 240 Diesel -83 -undecided-
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volvodspec
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Re: Primary CVT unit failure

Post by volvodspec » 05 Jul 2013 08:51 pm

the chamber in the primary unit is larger on the thicker hose side, so there's more room to fill with air.

if you can slightly pressurize the chamber via the smaller hose, and it holds that air for about 10sec then it's ok

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jtbo
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Re: Primary CVT unit failure

Post by jtbo » 05 Jul 2013 09:10 pm

volvodspec wrote:the chamber in the primary unit is larger on the thicker hose side, so there's more room to fill with air.

if you can slightly pressurize the chamber via the smaller hose, and it holds that air for about 10sec then it's ok
It is not much more than 10 seconds, but close there, pressure disappears slowly, when blowing to bigger connector pressure does not disappear so. I found out that from smaller connector air goes to bigger connector, very slowly. No differences when blowing from the hoses at engine bay and both sides are the same, so I guess it is normal.

Because of tachometric relay failure, I could not test if it would start to work. I post soon video to other thread about that.
Volvo 360GL -88 -under restoration-
Volvo 343DL vario -81 -running- Image
Volvo 240 Diesel -83 -undecided-
Citroen ZX Dturbo -97 -daily- ImageImage

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