Hi,

My brother drives an '95 850 turbo and has been leaking brake fluid. His independent in Palo Alto says that they need to replace the hydraulic unit (part: 30639115), which will cost $1700 plus labor--ouch! My initial reaction is that this unit, a part of the ABS system, would not cause the leak. More likely a leak in one of the lines/hoses, right? Any thoughts, or does this bullet have to be bitten?

Thanks!
Paul
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1982 240 DL (265K) , 1996 850 GLT (115K)

The service records of the previous owner of our car show the 'hydraulic modulator' having been replaced (for reasons I don't know).

Apparently the previous owner and Volvo went 1/2s in the cost as it was pretty expensive and probably the car was just out of warranty. So it does happen that these things need replacing.

Cheers, Phil
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'98 N/A S70 184,000Klm

yes--a big bummer. my brother will have to shell out 2K + to replace it. i wonder what makes these units leak...? this might be one of the not-often-discussed issues with 850s apart from the other well known big repairs (rear main, evap, etc.).

cheers,
pm
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1982 240 DL (265K) , 1996 850 GLT (115K)

When he says hydraulic unit, does he mean the master cylinder? Yes, the ABS attaches under it but not part of the "unit" per se. The price he quoted, no matter what part of the brake system he's talking about is way steep. You might try www.erievovo.com for a used unit and find another mechanic to do the r&r.
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1998 S70 T5 Emarald Green Metallic (125K), 2004 V70 2.5T Ruby Red (45K), Previous Owner of Black '94 850 Turbo Wagon (Sold at 140K and miss her). My cars have been running so well lately they've got me worried.

The part they are referring to is also called the "hydraulic modulator." I've never read about this being a weak point in the brake system. Cheers, and happy Labor Day.

PM
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1982 240 DL (265K) , 1996 850 GLT (115K)

I had my ABS pump/hydraulic unit replaced due to the leak of brake fluid from one of the 4 connectors to the caplier. There are 4 connectors in the pump for 4 capliers in the car. One of them in my 855 was leaking fluid slowly. Volvo garage tried to tighten the connector but it still leaked. So I asked them to replace the pump. It costed me about $2000 due to the expensive part. My car is equipped with TRAC so the part cost more.

Ching-Ho Cheng
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1995 855 NA, Bilstein Strut & Shocks, Volvo Protective Grill, K&N Filter, E-Code Lens, ClearCorner Light, Alpine CD-Changer, AutoDim RearView Mirror, 6000K HID

Thanks Ching-Ho. I'll deliver the news to my brother that this is a possibility. I don't suppose there is a work-around in the mean time: i.e., a way to fix the leak by disabling the ABS system (including the ABS pump) until 2 Gs get freed up.

Cheers,
Paul
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1982 240 DL (265K) , 1996 850 GLT (115K)

Call www.erievovo.com and see if they have a good used unit off of a wrecked 850. No sense in paying dealer prices. I've seen new units too for a lot less, but can't recall exactly where I saw them. Good luck and hope this works out for you.
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1998 S70 T5 Emarald Green Metallic (125K), 2004 V70 2.5T Ruby Red (45K), Previous Owner of Black '94 850 Turbo Wagon (Sold at 140K and miss her). My cars have been running so well lately they've got me worried.

Well, MIJ's advice to contact erievolvo was excellent. They have the hydraulic unit for $1000 used (but with lifetime warrantee; i.e., they send a new one out if the old one breaks, no pun intended). Thanks for the tip!

Cheers,
PM
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1982 240 DL (265K) , 1996 850 GLT (115K)

No problem, but wow...still $1000. I thought they would be much cheaper than that.
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1998 S70 T5 Emarald Green Metallic (125K), 2004 V70 2.5T Ruby Red (45K), Previous Owner of Black '94 850 Turbo Wagon (Sold at 140K and miss her). My cars have been running so well lately they've got me worried.

I think hydraulic unit refers to the ABS pump (according to my search with the part number). Can an ABS pump leak fluid externally? Could a '95 have an EBD valve that leaks?

Thanks.

Paul
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1982 240 DL (265K) , 1996 850 GLT (115K)

You can get a remanufactured master cylinder for under $200 and can install it in 1-2 hours including bleeding all the brakes.
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1998 Volvo S70