Vacuum hoses - Wich are the right products?

[matra530]

Once the carburettor was running properly and the tension on the throttle cable was correct again, I had to tackle the vacuum supply. The T-piece (split supply vacuum control and vacuum tank) was brittle. So I ordered a new part from my usual dealer.
However, the diameter of the connections to the front and to the tank is much larger, but the connection to the check valve is much slimmer... So I carefully applied some silicone grease to the old vacuum lines on the T-piece and Teflon tape on the other side towards the check valve, and sealed it with a clamp.
It worked. I took it for a test drive and on the way back it started to run unevenly at idle speed. I got out and heard a loud hissing sound.
The vacuum hose couldn't withstand the increased tension and ruptured.
Now I'm considering whether to replace just that one or all of them. At the dealer, a 40 cm piece costs €10. That adds up to quite a few pieces and will probably only be available by the metre. But what is the correct designation for the right metre goods?

Many thanks for any advice.

[roy4matra]

Once the carburettor was running properly and the tension on the throttle cable was correct again, I had to tackle the vacuum supply. The T-piece (split supply vacuum control and vacuum tank) was brittle. So I ordered a new part from my usual dealer.
However, the diameter of the connections to the front and to the tank is much larger, but the connection to the check valve is much slimmer...

That sounds like they have the T-Piece sizes the wrong way around!  Maybe the one they supplied was 13mm/10mm/13mm when it should have been 10mm/13mm/10mm.

So I carefully applied some silicone grease to the old vacuum lines on the T-piece and Teflon tape on the other side towards the check valve, and sealed it with a clamp.
It worked. I took it for a test drive and on the way back it started to run unevenly at idle speed. I got out and heard a loud hissing sound.
The vacuum hose couldn't withstand the increased tension and ruptured.
Now I'm considering whether to replace just that one or all of them. At the dealer, a 40 cm piece costs €10. That adds up to quite a few pieces and will probably only be available by the metre. But what is the correct designation for the right metre goods?

Many thanks for any advice.

The T-piece that has a fastening to the bulkhead, 0032602000, and has one hose to the vacuum storage tank, the opposite one to the white vacuum valve at the front of the car, and the third centre connection goes to the one way valve that is connected to the inlet manifold, has connection sizes 10mm/13mm/10mm.  The 13mm connection has a short hose to the one way valve, which is the same item as the brake servo one way valve, 0030581600.

If you simply purchase a standard 10/13/10 T-Piece which can be bought for under £5, you can fasten it to the bulkhead with a cable tie.  The original T-Piece fastening often breaks off anyway and has to be fastened that way in my experience.  A 10/13/10mm T-Piece can easily be found on the internet or from AFS (Advanced Fluid Solutions) or on eBay, or Mercedes used to have one available which I have the part number for, if you can't find another.

Roy

[Anders Dinsen]

That sounds like they have the T-Piece sizes the wrong way around!  Maybe the one they supplied was 13mm/10mm/13mm when it should have been 10mm/13mm/10mm.

The voice of an experienced mechanic understanding the nature of root causes! Thanks Roy for being so active around here

[matra530]

Hello Roy, thank you for your explanation. Unfortunately, the old T-piece could not be removed intact and its size could only be guessed at. Now, based on your measurements, I can confirm that the replacement part from Simon is too thick on both narrow sides and too narrow on the thick part. That's a shame, I'll have to look on eBay/Amazon etc. For the 10 mm pieces, can I also use vacuum lines with an inner diameter of 10 mm, or will that not be airtight?
Best regards,
Andreas

[roy4matra]

Hello Roy, thank you for your explanation. Unfortunately, the old T-piece could not be removed intact and its size could only be guessed at. Now, based on your measurements, I can confirm that the replacement part from Simon is too thick on both narrow sides and too narrow on the thick part. That's a shame, I'll have to look on eBay/Amazon etc. For the 10 mm pieces, can I also use vacuum lines with an inner diameter of 10 mm, or will that not be airtight?
Best regards,
Andreas

Here is the T-Piece at AFS:
https://www.advancedfluidsolutions.co.uk/10mm--13mm--10mm-reducing-t-piece-white-plastic-hose-joiner-barbed-connector-3-way-tee-bar-2307-p.asp

Ignore the photo which is a stock photo, as it looks like the two straight across ends are larger than the centre one, but the title and description shows it to be a larger centre connection 'reducing' to the size of the outputs.

Or here is one on eBay UK:
eBay item number 326584220799

somewhat dearer though!

Sorry that eBay URL link made the page far too wide.  I've change it to the item number now, so search for that instead.

The original rubber hoses or connecting pieces fit perfectly.  I have used one of these AFS ones for some years on one of my cars.

Roy

[matra530]

Thanks again for the informations. I found an old 10 mm T-piece in our workshop's stock. The memory and headlight control fit immediately, and to connect to the check valve, I inserted a narrower hose into the existing one (i.e. adapted it), and now everything is working as it should again. It's a shame that the detour was necessary.