Adding hose to release pressure from RMS?

rasense · Post by **rasense** » 02 Oct 2017, 22:36

Greetings all,

On another post I read a suggestion to fit a radiator hose to the top of the dipstick and route down through the engine compartment in order to relieve pressure on a leaking rear main seal.

I recently did my PCV system and the RMS seal started leaking since then. I'm guessing a clogged PCV had already damaged it, but pressure was being released through the oil cap seal (replaced that with PCV) and that may have brought the RMS to show its ugly face.

Any thoughts or experience on the hose from the dipstick pipe in order to relieve pressure on the RMS? Obviously not a permanent solution but anything to stop the leak from being as severe works for me until I have the cash to have it repaired, or the inspiration to do it myself. 1998 V70XC 230K miles.

Thanks in advance!

Post by **precopster** » 03 Oct 2017, 05:47

Can you explain the process to me in more detail? Makes sense but where do the fumes collect and condense?

Anything that cuts corners without damaging the air quality interests me.

Have you looked into any seal conditioners that may help? Over here in Oz we have this awesome company called Nulon that keeps spitting out great products. I used their seal conditioner on two different Volvo RMS (our 2006 XC90 2.5T and a 1998 V70R with just on 400,000kms I sold last year). On both of these the leaks were pretty bad.

Post by **erikv11** » 03 Oct 2017, 07:58

The dipstick hose usually vents to atmosphere down under the block. It can be smelly, even for the driver (think of how an exhaust leak in about that location is smelly), but it works to relieve pressure.

rasense wrote: ↑02 Oct 2017, 22:36 ... I recently did my PCV system and the RMS seal started leaking since then. ...

Longshots but:
- Are you sure the port into the block wasn't clogged?
- Are you sure the 2 hoses on top of the oil trap didn't get switched?

As for seal conditioners: Many, many people on this forum have had good a experience with "ATP AT-205 RE-SEAL," even with RMS leaks. You can buy it at auto parts stores now, used to be mail order only.

Post by **Clemens** » 03 Oct 2017, 11:25

+1 on RMS re-seal with ATP 205. It took like 20 hours or so, but it´s been dry for over a year now.

rasense · Post by **rasense** » 13 Oct 2017, 09:16

Thanks for responses. I am nearly certain that it is not the RMS and that there is something wrong with my PCV job. I cleaned the engine bay out really well and the seephole remains dry. I thought that it was the oil cooler lines, so I replaced them yesterday and took the car to work. Pushed it pretty hard. Still leaking. Going to pull the manifold again and make sure that the PCV ports are clear and that all hoses are connected properly.

Thanks again for the help. This forum is incredible, has saved me thousands, just wish I had been using it with my three previous 850s.

rasense · Post by **rasense** » 13 Oct 2017, 09:23

precopster wrote: ↑03 Oct 2017, 05:47 Can you explain the process to me in more detail? Makes sense but where do the fumes collect and condense?

Anything that cuts corners without damaging the air quality interests me.

Have you looked into any seal conditioners that may help? Over here in Oz we have this awesome company called Nulon that keeps spitting out great products. I used their seal conditioner on two different Volvo RMS (our 2006 XC90 2.5T and a 1998 V70R with just on 400,000kms I sold last year). On both of these the leaks were pretty bad.

The process that I was asking about is only a temporary fix to stop oil leaking/relieve pressure from RMS, but is not a fix that is good for air quality. Basically, the "fix" I saw was to remove the dipstick. fit a hose over the the dipstick tube and route it down through the engine bay to (I assume) get the gases out from under the car more easily (and not into the cabin) and so that oil does not bubble up and out of dipstick over the engine. Regarding environment, it is six one, half-dozen the other--oil dripping on ground from RMS leak vs. fumes being relieved through dipstick. The latter just might save your RMS until it gets fixed. Hope I was clear enough.