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91 S4 (Turq) has a leaky PSD fitting. Tried tightening the fittings and still getting some weeping - I think where the smaller fitting on the right side goes into the larger fitting in the left side.
Does this require some loc-tite or other sealant? Or do I need to get some new fittings?
That's your pressure valve. This picture may help; it shows the line as it connects to the valve. At the other end of that line is the PSD slave cylinder. I'm not sure where yours is leaking though. Is it in the middle of the valve or where the slave cylinder line threads into the pressure valve?
New check valves are still available. Not sure about the line to the slave.
Looks to me like it’s leaking at the fitting for the OE copper hard-line to the slave. If you’ve attempted to tighten this with the ‘two-wrench squeeze’ method and it’s still leaking then it’s likely you’ll need to replace one or both of the valve or hard-line. There’s probably a brake-fluid resistant Loctite sealant you could try. Would need to dig through the Loctite site.
Nice picture —-^ Ideally you’d use flare wrenches. More important for the little 11mm fitting on the hard line. The check valve ‘can take it.’
Absolutely correct. This was before I learned the lesson of a quality 11-mm flare wrench for swapping-out or bleeding the PSD. Pretty much anything PSD related.
Hi guys, this was pointed out to Eric by Stan when he brought that car down to Frenzy, we were changing all fluids and figured we try tightening this line up.
Yes we use flair nut wrenches, could not get any movement, and it does look like the seepage is coming from the middle of the pressure valve.
Nothing was done in this area per the original build, just driving it, it's is a blast w/ the GB stroked Eng.
With that said and what I'm reading here, it will require replacement?
I've never done one, will the PSD require a full bleed afterwords?
Is this under pressure w/out the engine running?
Eric, what happened in this area of the car just prior to the leak?
To my knowledge, nothing unusual. Either it has leaked ever so slightly since I've had the car or it just started. Never noticed a drip on the floor. As DaveK9 mentioned, Stan saw it when it was on a lift at Frenzy.
To my knowledge, nothing unusual. Either it has leaked ever so slightly since I've had the car or it just started.
Cool. Always good to know what wrenches have been recently in the area before rendering opinions.
Originally Posted by davek9
... it does look like the seepage is coming from the middle of the pressure valve.
With that said and what I'm reading here, it will require replacement?
That would be where I’d start.
I've never done one, will the PSD require a full bleed afterwords?
Not a full bleed. But, with the set-up time to do the partial bleed of the slave line you might as well do the full fluid replacement (that should be done every 2-3 years anyway.)
Is this under pressure w/out the engine running?
No. Nor is it under pressure when the engine is running. It’s only pressurized when you are bleeding the slave line or when the green PSD cluster light is on.
No. Nor is it under pressure when the engine is running. It’s only pressurized when you are bleeding the slave line or when the green PSD cluster light is on.
Pedantically, there may be residual pressure in the lines for a while after activation, but nothing close to the super-duper operating pressure.
And with the valve leaking, likely not even trivial pressure.
02-11-2019, 10:34 PM
PSD leaking (see pic)
This was before I learned the lesson of a quality 11-mm flare wrench for swapping-out or bleeding the PSD. Pretty much anything PSD related.
