Torque specs for A/C compressor

Joined
May 17, 2021
Location
VA
TDI
1998 VW Jetta TDI
Hi, I need to swap my A/C compressor on my 1998 VW Jetta TDI and I have a Haynes manual for it but the manual doesn't say how to remove or install an A/C compressor. I have researched it thoroughly enough to do it myself except I can't figure out what the torque specifications are for the A/C compressor or the A/C lines. Maybe it says in another manual.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
SO, as a rule of thumb, aluminum fitting lines is about hand tight with a drop of PAG oil on the threads. there are o'rings on ALL of the connections so tight threads are pointless. like how are you going to measure the torque you put on them? been doing AC on these cars for a while now. never had an issue with hand tight.

anything past hand tight, and i mean once the threads stop moving pus a tiny bit.. is going to strip them or bend the lines. always use 2 proper fitting crow foot wrenches.
 
Joined
May 17, 2021
Location
VA
TDI
1998 VW Jetta TDI
Is that the same for the A/C compressor mounting bolts? I don't think they have o-rings on them.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Is that the same for the A/C compressor mounting bolts? I don't think they have o-rings on them.
All ac fittings on these cares are orings not flares.
So yes. Dont go nuts. The ac compressor bolt for the hold down and the bolts for the expansion valve you can treat normally as per the size of the bolt to normal torque value
Aka 8 to 80 ftlb for the m8 bolt on the valve and like 20 to 25 for the ac compressor.
Good enough is fine here. Dont go overboard.
The mounting bolts you can snug down normally as they actually pull in the sleve they thread into to pinch and hold the compressor. Too much and you will spin the sleve and it will never come out! Not sure on the value on those but again just dont go nuts.
 

JoeMama369

Member
Joined
Jul 24, 2021
Location
Pennsylvania
TDI
1998 MkIII VW Jetta
The A/C compressor mounting bolts do NOT have an o-ring. I am balls deep in repairs with both my compressor and water pump removed and also looking for the torque spec of the A/C compressor mounting bolts...
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
The 'front' bolts are M10x112 and 33 ft lbs
The compressor support bracket at the rear has two bolts, M10x30, both are 33 ft lbs.

I usually just make sure they're tight, and make sure the threaded slide bushing is backed out enough to allow the compressor to be mounted without binding.

EDIT: water pump mounting (bolt or stud) 15 ft lbs plus an additional quarter turn.

Accessory bracket mounting nuts 22 ft lbs

Good luck

Steve
 
Last edited:

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Aka 8 to 80 ftlb for the m8 bolt on the valve
Not sure which valve you’re referring to, but I’d love to see any m8 bolt that gets torqued to 80ft/lbs.

Seriously, do people torque every bolt to spec? For those that do, how often are you getting your torque wrenches calibrated?

These cars and the hardware is old, worn, rusted, etc. I doubt these torque specs even count, at this point. Other than engine internals or new crank bolts, I rarely break out the torque wrench. This is my opinion, so don’t follow my lead... do what the Bentley tells you to do...

-Todd
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
Not sure which valve you’re referring to, but I’d love to see any m8 bolt that gets torqued to 80ft/lbs.

Seriously, do people torque every bolt to spec? For those that do, how often are you getting your torque wrenches calibrated?

These cars and the hardware is old, worn, rusted, etc. I doubt these torque specs even count, at this point. Other than engine internals or new crank bolts, I rarely break out the torque wrench. This is my opinion, so don’t follow my lead... do what the Bentley tells you to do...

-Todd
Actually I don't follow torque specs much either. I generally do 'tight' by feel unless there's a reason to do it with a torque wrench. I also only have old school torque wrenches so that's limiting as well. I try and remember what level of difficulty I had removing the bolts and mimic that when reinstalling...then give it a little extra. For bolts into aluminum housings I am pretty careful, I try and clean all the bolts so there's no breakage or stripping out.

I guess I do have a 3/8" KD 3460 torque wrench but IIRC it needs to be serviced for a handle issue.

Steve
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
I’ll use a torque wrench when it’s a critical part, otherwise I usually go by feel. Injector bolts, absolutely. Valve cover bolts, nope. I make sure not to overtighten them (common issue) and cause a leak, but there is no reason snug isn’t good enough.

however, when working on someone else’s car I usually do use a torque wrench on everything and I don’t want any reason something could go wrong.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
The last time I used a torque wrench on a noncritical part, I got burned.

I was assembling an engine for a Rabbit GTI, and figured I’d do the “right” thing. A few months later, the M6 bolts backed out, on the rear seal carrier. I needed to pull the trans and clutch to see where the oil leak was coming from. This wasn’t that long ago, and this was the first time I ever used a torque wrench on this part in my 25+ years of VW ownership. Never again...

It’s the same seal carrier that’s used on these engines. Since it was apart, I upgraded to the A4 Teflon seal/carrier.

-Todd
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
The last time I used a torque wrench on a noncritical part, I got burned.

I was assembling an engine for a Rabbit GTI, and figured I’d do the “right” thing. A few months later, the M6 bolts backed out, on the rear seal carrier. I needed to pull the trans and clutch to see where the oil leak was coming from. This wasn’t that long ago, and this was the first time I ever used a torque wrench on this part in my 25+ years of VW ownership. Never again...

It’s the same seal carrier that’s used on these engines. Since it was apart, I upgraded to the A4 Teflon seal/carrier.

-Todd
I also tend to think the torque specs are a tad low...IMO.

Steve
 
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