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Discussion Starter · #1 · (Edited)
This is a DIY cap-hose combination, to bleed the hydraulic system using an existing Air Compressor.

In theory, you can use "Motive Power Bleeder", which is nothing more than a modified garden sprayer bottle. However, it costs around US $50 or so.

But for those who already owns an air compressor, you can do the following DIY, this way you:
- Can invest minimally using my DIY (about $15 total)
- Do not have to clean the Motive Bleeder after the job. Also keeping the Motive Bleeder Bottle clean for the next 2 years (until you beed again) can be a challenge (dirt collecting inside the bottle etc.).
- Using my DIY cap-hose combination, you simply bleed and then store the DIY cap-hose combination away after use. Just use a ziploc bag to cap both ends and tie it so dirt does not get in this device.

General Notes:
- Brake Fluid is very corrosive to paint work, so wipe off any spill on paint work ASAP.
- Use a small funnel to pour brake fluid into the reservoir to avoid spill.
- Wrap the area around the reservoir with some rag to absorb any spill.
- The Air Compressor: use minimum 10 psi, max 15 psi. Do NOT exceed 30 psi (risk of damage to reservoir although I do not know for sure what pressure it takes to rupture the reservoir).
- Do not ever allow air to enter the hydraulic ABS system, because once air is inside the ABS Modulator, it is very difficult to get rid off. If you allow air to enter the ABS Modulator, then you need to visit the dealer so they can use their computer device to bleed the air out of the ABS Modulator. Now you are talking big expense!
- If you fill Brake Fluid to within 1 inch of the cap, you can safely bleed using the standard small catch container as in the pic (sold at many auto parts store) twice before refilling the Brake Reservoir again.
- When in doubt, stop and check the reservoir to be sure it does not fall below "Min" level.
- Do this on a dry day so moisture from the air does not enter the compressor. Avoid rainy days at all cost!!!
- I have a 1998 BMW 528I and 1998 Volvo V70, with both using ATE Brake System. So buy the standard 45-mm ATE cap from FCP Groton (or local Volvo dealer). Just get the cap from a 1991 Volvo 240 or 740. Back then those caps did not have Brake Fluid Level sensor. It was a plain simple 45-mm cap.
- This 45-mm cap can be used to bleed hydraulic system in any car with ATE reservoir such as: MB, BMW, Audi, VW, Volvo, SAAB etc. Check to be sure if using it on other cars. Japanese cars use different caps.



1. To make my DIY cap-hose combination:
- ATE Brake Reservoir Cap from FCP Groton or local Volvo dealer; Volvo PN 1272107, used in many Volvo cars since 1960's through 1990's ($5.00):
http://www.fcpgroton.com/search.php?nodecode=true&search_term=1272107&do=search
- Compressor Hose ($6-7 at my local Menards hardware store, or Harbor Freights etc.). EDIT: You may not need this hose at all (see EDIT below in follow-up post).
- 1/4-inch nut ($1.00)
- 1/2-inch washers ($1.00)


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- Drill a 1/2-inch hole in the ATE cap and clean any debris.
- Use the Air Hose Male end and insert into the cap, washer on both sides.
- Small bead of Silicone under each washer and the hose male end's threads.
- Tighten the 1/4-inch nut hand tight.
- Let the Silicone Caulk cure for one day before using it.



2. To bleed:
- Open the bottom drain valve of the Air Compressor and turn the Air Compressor on to expel any water inside the Air Compressor. Then close the bottom valve.
- Keep air pressure within 10-15 psi (this works best for me). Do NOT exceed 30 psi!
- Using a Turkey Baster, suck out as much old brake fluid from reservoir as possible.
- Using a Small Funnel, add Fresh Brake Fluid until it is about 1 inch from the top. Avoid spilling or overtopping!
- Attach the cap-hose combination.
- Connect to Air Compressor using the quick disconnect.
- Keep air pressure within 10-15 psi!!!



- Start bleeding, remember you can bleed about 2 small containers before you need to refill.
- To refill reservoir, disconnect air hose at "quick disconnect", refill reservoir to within 1 inch of the top. Re-connect hose.
- For each car, I use about 70-80% of the 32-Ounce (946 mL) Brake Fluid Bottle. I use Valvoline Synthetic Brake Fluid (DOT 4).

Good Luck and enjoy this one-man kit if you already own an air compressor. It is a breeze to bleed the brake this way!
 

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BTW, I never put brake fluid into the Motiv bleeeder. I use it exactly as this DIY does, as air pressure only. Guess I spent an extra $40 for the confidence that I will not over pressure the reservoir.
CL
 

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Discussion Starter · #7 · (Edited)
BTW, I never put brake fluid into the Motiv bleeeder. I use it exactly as this DIY does, as air pressure only. Guess I spent an extra $40 for the confidence that I will not over pressure the reservoir.
CL
For those who want to build a "pressurizer" using garden spray bottle, here is the DIY:
http://www.bmw-m.net/TechProc/bleeder.htm

I already have an air compressor and am very happy with my DIY.
I bled my 1998 Volvo V70 and 1998 BMW 528i yesterday.
It took about 30 minutes/each car.
Now I don't have to bother my 10-year-old son to pump the brake pedal any longer!

PS: I forgot to mention that my E39 can be bled with car on the ground, no need to lift it up. For FRONT wheels: turn wheel to opposite direction (For Right Front, turn wheel to LEFT to expose the bleeding nipple). The REAR Wheels are straightforward.
 

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Discussion Starter · #8 ·
Update,

If you already have a hose and quick disconnect (you should) from your air compressor, then no need for the another yellow air hose as in my pics above.
You can simply buy a 1/4" NPT fitting for $0.50 (or buy a kit for $3.99 at Harbor Freight) and attach it directly to the brake cap:

 

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Freude am Fahren
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Cool. I need to do my fluid; no idea when it was last done. For all I know it's the original stuff o_O!
 

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Discussion Starter · #10 ·
For those who want to buy Motive Bleeder for $50:
http://www.fcpgroton.com/product-exec/product_id/22523/nm/Motive+Power+Brake+Bleeder
Here is a simple math:

- Motive Bleeder $50-55.

My DIY:
- ATE Cap $5, 1/4" NPT Fitting $0.50, 1/2" Washers $0.50.....$7.00
- Now you have extra cash for a pancake air compressor...if you look hard enough (sales at hardware store or Sears etc.) you can buy a pancake air compressor for $45-50 range.

Now you have the extra pancake air compressor for many other uses: tire inflation, air tools in home remodelling projects (if you care for it!), brake bleeding (of course).

See? win-win situation with my DIY. If you already budget $50 to buy Motive bleeder, stop!!! Do my DIY: this way, now you have a pancake air compressor for free!
 

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Nice ideas... I like being able to replace the brake fluid while pressurizing the system. It is a pain in the a$$ to pop the top off the mc and refill. You don't EVER want to push air into the system:
Here is my DIY pressure bleeder:










Bottom line: You should change your brake fluid every 2 years. It doesn't matter how you do it, just do it.
 

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Discussion Starter · #12 ·
Max_VQ,

Nice setup, similar to Motive Bleeder.

With my DIY, there is nothing to clean after bleeding.
The slight downside of my setup: refills 3-4 x during the bleeding process. Each refill is quick:
- remove cap: 3 seconds
- fill more brake fluid: 10 seconds
- recap: 3 seconds

The time I "lose" to do the brake fluid refills (16 seconds x 4 = approx 1 minute) is gained by the fact that I do not have to clean the fresh fluid bottle (The "Rona" bottle in your pic)......hehe.

Anyway, whatever trick (Motive Bleeder or my DIY) works. As I mentioned above, by doing my trick, you have budget for a pancake air compressor for free!
 

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hey guys just curious...I was online and saw a diy of a guy using a oil pump can filled with BF. he was pumping it in from the bleeder valve side saying that air "likes to travel up." What do you think about that Idea. He said it game the BEST BLEED for cars taking ALL air out of the system.
 

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hey guys just curious...I was online and saw a diy of a guy using a oil pump can filled with BF. he was pumping it in from the bleeder valve side saying that air "likes to travel up." What do you think about that Idea. He said it game the BEST BLEED for cars taking ALL air out of the system.
My 2 cents:
Sounds messy to me. Once the bleeder nipple is open, you don't have a perfect seal between the caliper and the nipple. A lot of Brake fluid will drip out...
 

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Discussion Starter · #15 ·
hey guys just curious...I was online and saw a diy of a guy using a oil pump can filled with BF. he was pumping it in from the bleeder valve side saying that air "likes to travel up." What do you think about that Idea. He said it game the BEST BLEED for cars taking ALL air out of the system.
It is basically non-sense! The idea is to bleed from the caliper UPWARD. Pumping fluid into the brake caliper nipple pushing it up. The problem: it brings water/moisture (which tends to collect inside the caliper because of the road condition) upward into your ABS Modulator etc.
Eventually it will be expelled out but it makes bleeding unnecessarily complicated. It is otherwise known as "Reverse Bleeding".

With the conventional bleeding from the Reservoir toward the brake caliper, any air trapped in the line is pushed down into the caliper and out of the nipple.
The conventional technique works well for thousands of cars, so stick with this technique.
 

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I don't know....now the way you guys are talkin is the best and cleanest way? I am trying to fully understand it. you use the compressor to pressurize the system through the cap after topping it off? can you describe the science of what is going on?


******update....*****either way i am going to go home tonight and make one....I am changing to steel lines******88
 

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Discussion Starter · #17 ·
I don't know....now the way you guys are talkin is the best and cleanest way? I am trying to fully understand it. you use the compressor to pressurize the system through the cap after topping it off? can you describe the science of what is going on?
1. The classic way: 2-man technique:
One person depresses the brake pedal (with a small piece of wood under the brake pedal to prevent over-travel of the pedal) while the other person bleeds from the caliper.
The problem is: you need an assistant, which is not always available.

2. The one-man technique using a pressurizer as mentioned in this thread. No need for 2nd person. Options:
a- Garden Sprayer (Motive Bleeder)
b- Air Compressor

3. Reverse bleeding like you just mentioned. Stay away from this urban legend.

Anyway, you might want to visit this library by Larry Carley to catch up on some car repair readings. There is a wealth of info here written by the American guru Larry Carley:
www.aa1car.com/library.htm
 

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Hey thanks for the information. I did it before of course being a car owner but never really understood the complete science behind it...I thought about it last night and understood that the way i asked the question was VERY elementry at best. I got most of the stuff to make it yesterday just waiting for the cap that I might have to order online. Thanks for the information on the GRRREAT DIY. You guys love to know what is going on with your car...and that is why I like it here...king


******oh and this is a good guide....thank you for the extra information*****
 

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Discussion Starter · #19 · (Edited)
Hey thanks for the information. I did it before of course being a car owner but never really understood the complete science behind it...I thought about it last night and understood that the way i asked the question was VERY elementry at best. I got most of the stuff to make it yesterday just waiting for the cap that I might have to order online. Thanks for the information on the GRRREAT DIY. You guys love to know what is going on with your car...and that is why I like it here...king

******oh and this is a good guide....thank you for the extra information*****
For small part like this, go to local Volvo dealer and order Volvo PN 1272107 (ATE Cap) for $5.00.
This ATE cap goes way back to 1960's when ATE made brake reservoir etc. for many European cars (Vovlvo, VW, Audi, MB, Mercedes etc.).
They may not have ithe brake capin stock, but they can order it for you.
You can even order on the phone and come and pick it up when it is in.

Whatever it is, read my DIY carefully. I took alot of care writing it in detail.
Do not exceed 20 psi.
Best is 10-15 psi.
 
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