Brake fluid reservoir cleaning

[Hebaristo]

Hi guys, I'm taking advantage of the weekend to do maintenance tasks on my 97 940 lpt. Renewing the brake fluid. Yesterday I vacuumed part of the brake reservoir, my surprise was that there is a part of the reservoir that does not come out vacuuming, I suppose it is the part that feeds the ABS. My question is, how do you get that fluid out of the brake reservoir? I suspect by pulling the reservoir up and dislodging it from the master cylinder. If so, should I bleed the master cylinder afterwards? This one has two purge nipples, how should I purge? Your answers will be appreciated

[Laird Scooby]

Originally Posted by Hebaristo

Hi guys, I'm taking advantage of the weekend to do maintenance tasks on my 97 940 lpt. Renewing the brake fluid. Yesterday I vacuumed part of the brake reservoir, my surprise was that there is a part of the reservoir that does not come out vacuuming, I suppose it is the part that feeds the ABS. My question is, how do you get that fluid out of the brake reservoir? I suspect by pulling the reservoir up and dislodging it from the master cylinder. If so, should I bleed the master cylinder afterwards? This one has two purge nipples, how should I purge? Your answers will be appreciated

After doing what you've done, the whole system needs bleeding already. Best bet is buy a Gunsons Easibleed and follow the instructions that come with it.

[Hebaristo]

Originally Posted by Laird Scooby

After doing what you've done, the whole system needs bleeding already. Best bet is buy a Gunsons Easibleed and follow the instructions that come with it.

Thanks for your reply Laird. I have a power bledeer to bleed the system. I have not managed to separate the brake fluid reservoir from the MC, when you say bleed the entire system, do you also mean the MC?

[Laird Scooby]

Originally Posted by Hebaristo

Thanks for your reply Laird. I have a power bledeer to bleed the system. I have not managed to separate the brake fluid reservoir from the MC, when you say bleed the entire system, do you also mean the MC?

My previous reply was deliberately brief to try and avoid ambiguity. Here's the longer version :

First, you shouldn't ever need to separate the reservoir from the master cylinder in normal service, only for repairs or replacement of the master cylinder.

Second, by vacuuming it out, you have already introduced air into the entire brake system. As such, it will need bleeding in its entirity to ensure removal of all air and contaminated fluid from the system.

When you say you have a power bleeder, what exactly do you mean? Certain types of these won't work particularly well with the Bosch ABS systems used on the 7/9xx ranges, particularly if they are the vacuum variety that apply vacuum to the bleed nipples.

My advice to you now would be, firstly remove the brake light fuse and then top up the master cylinder and weddge the brake pedal down overnight. Remove the wedge next day, refit the brake light fuse and ensure the brake lights work again.
Now, preferably using a Gunsons Easibleed, bleed the system starting with one rear wheel, then the next then move onto the front ideally in the same left-right or right-left order that you did the back end.
Neither of the Bosch ABS systems will tolerate "live bleeding" so make sure the ignition key is out of the car. You may get away with it (or appear to) once or maybe even twice but you may also cause damage that will be unseen for some considerable time.

Hope that makes things clearer!

[Hebaristo]

First of all thank you very much for your answers, you are a source of wisdom for Volvo!
Forgive me if some of your indications I do not understand perfectly, since I use Google translate to read and write the answers.
I have a power bledeer that wields pressure in the liquid reservoir. At the end of the message I attach a photo of my bleeder.
-Remove the brake light fuse, it refers to the fuses behind the ashtray or disconnect the brake switch next to the pedal.
-The wedge to press the brake all night means that you put weight on the pedal so that it stays down or that you put a wedge behind the pedal so that it does not make too much travel and risk breaking the lips of the master cylinder ?
I hope you don't feel overwhelmed by my questions, just that as I said before Google translate sometimes translates like crap.
Best regards!

[Laird Scooby]

Originally Posted by Hebaristo

First of all thank you very much for your answers, you are a source of wisdom for Volvo!
Forgive me if some of your indications I do not understand perfectly, since I use Google translate to read and write the answers.
I have a power bledeer that wields pressure in the liquid reservoir. At the end of the message I attach a photo of my bleeder Very similar to a Gunsons Easibleed!


-Remove the brake light fuse, it refers to the fuses behind the ashtray or disconnect the brake switch next to the pedal. Either method or remove the brake light bulbs - it's to prevent the battery being discharged by the brake lights being on overnight.



-The wedge to press the brake all night means that you put weight on the pedal so that it stays down or that you put a wedge behind the pedal so that it does not make too much travel and risk breaking the lips of the master cylinder ? Use something to keep the pedal as far down as it will go overnight. This opens the valves in the master cylinder so any air you have introduced by vacuuming it has a chance to escape overnight, aiding the bleeding process



I hope you don't feel overwhelmed by my questions, just that as I said before Google translate sometimes translates like crap.
Best regards!

I've added my answers into the quote of your response in blue above, sometimes Google translate is very good, other times incredibly bad!

Something that makes me laugh about Google Translate is the people who use it to translate a meaningful expression into Chinese or Japanese and it displays a letter/word in one of those languages that actually says "Google Translate can not translate this" - they then have this letter or word tattoo'd on themselves.

[Hebaristo]

Hahahahahaha.. Your example on Google translator is very good.
Completely clarified doubts. I hope you are doing well, thanks again!
Cheers!!