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Jbaumshelter

Bolt Sizes for A/C Bracket

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Does anyone know the bolt size & length for the A/C bracket? Specifically the upper bolts for the late model cars that are located just under the exhaust manifold. I am installing a Hobbie Dave bracket on a 1975. 

 

 

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From the documentation included with my Hobie Dave bracket:

 

All metric.

10-1.50 x 40 bolts you need 2 attaches the compressor to the adjustable

end of the bracket arm.

10-1.50 x 35 bolt you need 2 mounts the compressor to the middle holes in

the bracket.

10-1.50 x 30 bolts you need 2 mounts adjuster arm to the bottom of the

bracket.

10 mm washer you need 6

10 mm lock washer you need 6

10- 1.50 nut you need 6


 

to mount the bracket to your engine you will need:

8-1.25 x 16 bolts you will need 2 for the top holes

8-1.25 x 20 bolt you will need 1 for the bottom You will also need two 8mm washers to offset the motor mount bracket.

The hole that sticks out from the side of the bracket uses the front bolt

from the motor mount. Also always make sure when you mount the compressor that the compressor ports are oriented to the top within reason. That’s where the hoses attach so all the pag oil does not get pumped out in to the system. All that should cost you around 12 bucks at ACE

hardware.

The belt size for the 2002 is Dayco top cog #17320

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That's exactly what I was looking for. Thank you. I got my bracket a few months ago but didn't get any documentation with it. This is perfect. 

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4 hours ago, Jbaumshelter said:

That's exactly what I was looking for. Thank you. I got my bracket a few months ago but didn't get any documentation with it. This is perfect. 

 

Me too. Thanks for the info. 

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7 hours ago, Simeon said:

Me too. Thanks for the info. 

 

Simeon, 

I got this done today. I used block studs instead of the bolts suggested. Either way works, I just felt better about that. coloincaalpine on the forum suggested it and it made sense to me. 

 

Word to the wise, make sure your front right motor mount is in good shape. One of the bolts in the bracket attaches to that motor mount. My was shit. When I removed that bolt the engine dropped at least 1". That got "not fun" real quick. I would suggest getting a piece of wood and jack underneath your oil pan and take the weight off the motor mount before removing just in case. 20 minute job turned into 2 hours. But hey, At least I now know I desperately need to replace my motor mounts before I shove my fan into my radiator. Best of luck.

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At last Saturday's Houston BMWCCA get together I heard a horror story from someone with a HobieDave bracket where on the way to MidAmerica he had problems with the bolts backing out - in the end he sheered off the AC lines! After locktite and other methods failed he tried using safety wire - and ended up with the bolt breaking. I just mention this as 2nd hand information, but it sounds like getting the bolts properly torqued and secured is non-trivial. I've only owned my 02 for less than 2 months, and have a lot to do before I'll be ready to move on my plans to add AC to it. Anyone else run into this, or was this guys car just possessed? Now that we have the fastener specs, anyone have the torque specs for them?

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16 minutes ago, BarrettN said:

At last Saturday's Houston BMWCCA get together I heard a horror story from someone with a HobieDave bracket where on the way to MidAmerica he had problems with the bolts backing out - in the end he sheered off the AC lines! After locktite and other methods failed he tried using safety wire - and ended up with the bolt breaking. I just mention this as 2nd hand information, but it sounds like getting the bolts properly torqued and secured is non-trivial. I've only owned my 02 for less than 2 months, and have a lot to do before I'll be ready to move on my plans to add AC to it. Anyone else run into this, or was this guys car just possessed? Now that we have the fastener specs, anyone have the torque specs for them?

 

I would use the standard maximum torque  for that size and grade of fastener. This can just be looked up on the internet. There is also a section in the BMW shop manual that gives standard torque values for fasteners. 

 

I have a lot of faith in quality lock nuts, spring washers, Locktite of various grades    , even safety wiring when chosen for the application and used correctly.

 

Clean bolt holes with Locktite applied to clean bolts prior to torquing to specification is a reliable way of retaining much more critical bolted connections than this one. 

 

Assuming that the bolt wasn’t damaged by over-torque when installed, the force required to break a single M8 bolt would be far beyond anything the bracket and compressor are capable of applying. My guess is that the bolt had been damaged previously. 

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18 minutes ago, coloincaalpine said:

A/C brackets should be studded whenever possible, or..........................they snap or back out.

IMHPO

 

This is the direction that I went. The one true reality for this bracket is that the bottom bolt attaches to the motor mount. If you have a bad motor mount, all the stress is applied directly to this bracket and the bolts/studs that are holding it in. I got to witness that happen first hand last night when I installed mine.

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Forgot to mention that these are 8mm bolts. 10 or ever 12mm into the block would be much better. No options there but adding a lot of stress on 8mm bolts didn't feel like a great idea. I even worry about 8mm studs. 

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Lol I am the person who keeps having bolt problems. I am now running grade 11 with coiter pins. 

 

Only the top bolts that hold the compressor tend to come loose. 

 

The compressor is alot of vibrating weight hanging off the engine and bolts will work them selves loose 

P_20190211_161947.jpg

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