Flushing the Brake Fluid / Brake Inspection

sikwan

06 T1N Can
My 2006 was purchased 3/2006. It's now 2009 with 32,000 miles and I thought it would be a good time to flush the brake fluid and do a visual inspection of the brakes.

I purchased the Mityvac MV6835 for $123.57, no tax, free ship.

This is all the items that I got in the box with two booklets of instructions.

I first did my flush and inspection from the back. Usually it's better to do the flush starting from the brake that is farthest from the master cylinder, which is usually the passenger rear on left hand drive Sprinters. But as I realized later this may not be the case for the Sprinter.

Passenger side rear brake.
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T50 bolt holds the rotor.

18mm bolts (2x) that hold the caliper
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Still a lot of meat on the pads.
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Close up of disc (left) to sensor (right) distance.
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The ATE brand stamped on the left side of the caliper.

Driver side rear brake.
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I removed the caliper and removed the T50 bolt so that I could remove the rotor to do a visual inspection of the parking brake shoes. I hit the rotor around the circumference of wheel mating surface with a rubber mallet to see if I could knock it lose. With the parking brake disengaged, I couldn't get the rotor off. I spun the rotor and lightly tapped the braking surface with the rubber mallet, but I still couldn't get it to come off. :hmmm:

Since the rear pads were still good, I'm sure the brake shoes were in good condition. I'll have to revisit this with a rotor removal tool as I needed to get the flushing done.
 

sikwan

06 T1N Can
Driver side sensor (left) to brake disc (right) distance.
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You can barely see the ATE stamped on the right side of the caliper.

Pad still has meat on it and rotor looks good.
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Now for the real stuff...

11mm to open the bleed nipple for all four corners.
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Galfer Super DOT 4.
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I bought each bottle for $5.99 / 17.64oz from rockymountainmc.com.

The old fluid currently between the Max and Min lines.
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sikwan

06 T1N Can
The filtering screen on the master cylinder bottle.
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I needed to remove it for the Mityvac bottle attachment.
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The fluid had a hint of brown in it. Time to change it.
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Left the filter on the reservoir cap.
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I sucked out as much as I could of the old fluid with a rubber syringe.
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I think it'll be easier using the extra Mityvac hose to do this. I wasn't thinking at the time.
 

sikwan

06 T1N Can
Attached the Mityvac bottle to the reservoir with two bottles of the Galfer Super DOT 4 fluid.
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The nozzle end was between the Max and Min lines. The valve was opened.

As the instructions say, it's normal to see fluid and bubbles flow through the tube because air is coming through the nipple threads. The instructions say to use silicon grease around the threads to prevent air from leaking into the tube. Others have mentioned to use teflon tape on the threads. I didn't use either and once I thought about it, as long as I...

create a vacuum on the hose attachment before opening and after closing the nipple, air should not get into the system.

I did just that and I verified it with my wife pumping and holding the brake pedal while I opened the nipple. No air bubbles exited. It certainly would've made the flush faster if I had the threads sealed.

11mm wrench with vacuum attachment.
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The setup.
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Once I connect the air hose to Mityvac attachment and push the lever to on, the clear hose starts to evacuate by vacuum.

I open the nipple. Fluid and air (from threads) start to flow.
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Close up of the old fluid being evacuated from the system and air (from threads).
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sikwan

06 T1N Can
The bottle gurgles during the evacuation process.
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I finish both sides of the rear brake using two bottles (probably less).

The dirty fluid.
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Now for the front brakes...

Passenger side sensor (left) to disc rotor (right).
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Passenger caliper.
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Now I know what type of pads I need to buy when it comes time.
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sikwan

06 T1N Can
Passenger side, outside surface of disc rotor. Looks good.
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Passenger side, inside surface of disc rotor. Looks good.
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Driver side, outside surface of disc rotor. Looks good.
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Driver side, inside surface of disc rotor. Looks good.
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Driver side, disc rotor (left) to sensor (right) distance.
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sikwan

06 T1N Can
I don't expect it to be any different on the driver's side front caliper, but you never know.
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Driver side front caliper.
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The fronts didn't take much to flush.
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There's probably more clear than brown to this fluid.

I finished the project by rinsing the filter with the Galfer fluid.
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I finished everything up and and went for a drive. The brakes worked like before.

Some thoughts:

1. If I wasn't doing a visual inspection (or taking picture for this write-up for that matter), I think I could've done it without removing the wheels.

2. It would have been better to activate the ABS, via DRBIII, to agitate the fluid inside the ABS during the flush, but it's better than nothing.

3. For this exercise, I started the flush at the passenger side rear brake because it's the farthest from the master cylinder. Only thing is, all brake lines in the Sprinter extend from the ABS unit (right under the master cylinder), individually, to each brake at each corner. There's no T-connection of any sort that separates a line going to the back, so I'm not even sure starting from the farthest from the master cylinder has any merit at least in this Sprinter exercise.

4. A different colored brake fluid would certainly make it easier to see than going from dark yellow to light yellow.

5. It would be good to run the flush and to let the compressor rest. I don't have a 100% duty cycle compressor. Although it is an oil filled (quieter) compressor, I do worry about it blowing up midway through the flush. To create that vacuum, a lot of air is needed so my compressor is running constantly during a single brake flush.

6. I think 4 bottles of the Galfer (17.64oz) fluid was enough for this flush.

Side note:

I had enough spare fluid to flush a 2004 Subaru Forester brake system (never has been done before) with wheels on and the hydraulic clutch on a 1997 S10 NV1500 (flushed manually 5+ years ago. it was black coming out) all on the same day. The S10 brakes were already flushed out to get ready for the Sprinter.

The Mityvac certainly does the job much faster than the normal pump & hold method.
 

Ciprian

Spark Plugs not allowed!
So, what is the difference between DOT 4 and DOT 4+ fluid? Can DOT 4 be used?
 

rlent

New member
Nice write up Seek !
 

sikwan

06 T1N Can
So, what is the difference between DOT 4 and DOT 4+ fluid? Can DOT 4 be used?
The difference is temperature.

Theoretically the two are compatible, which means you can mix them, but you'll be lowering the boiling point if you use regular DOT 4.

DOT 3, DOT 4, DOT 4 Plus (or Super DOT 4), and DOT 5.1 can be mixed. Only thing I've found is that they differ in temperature boiling points. They are all polyethylene glycol based. User Amauri is using DOT 5.1.

DOT 5 cannot be mixed with the above, because it's silicon based.
 

jdcaples

Not Suitable w/220v Gen
Excellent write-up, Seek. Thank you!

-Jon
 

KL2BE

New member
Great write-up :popcorn: :rad: :cheers: !
These shared tutorials are worth a great deal and very much appreiated by a lot of folks :clapping:.
Since my Sprinter ('06 chassis) has only 25,000 miles my first break-flushing project should be my 15 year-old Isuzu Trooper with 90,000 miles; I imagine it's fluid is looking a bit off color by now :eek:.
 

abittenbinder

Doktor A (864-623-9110)
Please read my Tech Alert on this brake flushing subject so you can decide when to 'DIY' this procedure and when you should visit a technician.

I would also caution DIY'ers without ESP, to temporarily secure the ALB's rear brake proportioning valve lever (using a wire or tie) to the full load position to allow proper pressure or vacuum extraction of the old fluid. Doktor A
 
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cdman1674

Member
Doktor A,
I asked my dealer what equipment they use to do a brake flush as was told that they don't have a special piece of equipment. They use the "SCAN TOOL" to activate the sprinters brake pump and flush it that way? This doesn't sound like the use of the "factory DRBIII " or is it?:thinking:
Thanks Chris
2004 142,000 miles
 

abittenbinder

Doktor A (864-623-9110)
Doktor A,
I asked my dealer what equipment they use to do a brake flush as was told that they don't have a special piece of equipment. They use the "SCAN TOOL" to activate the sprinters brake pump and flush it that way? This doesn't sound like the use of the "factory DRBIII " or is it?:thinking:
Thanks Chris
2004 142,000 miles
The 'scan tool' your Sprinter dealer is referring to is the DRBIII (for pre-'07 Sprinters).

The DRBIII activation of the ABS pump and solenoid valves should be done in conjunction with pressure bleeding using a commercially available generic pressure bleeding/flushing device. I would not recommend using the ABS pump alone to move the quantity of brake fluid necessary to completely flush the system of old fluid. Doktor A
 
3

312 diesel (closed)

Guest
Please read my Tech Alert on this brake flushing subject so you can decide when to 'DIY' this procedure and when you should visit a technician.

I would also caution DIY'ers without ESP, to temporarily secure the ALB's rear brake proportioning valve lever (using a wire or tie) to the full load position to allow proper pressure or vacuum extraction of the old fluid. Doktor A
If the fluid is flushed without the DRBIII tool don't the remnants of the old fluid just get flushed into the system as the van is driven. Presumably if that is the case then regular maintenance will be adequate to maintain a satisfactory brake fluid condition?

However, if you break into the systen does this mean the system cannot be purged of air without the ESP tool? That could be a real pain for the DIY mechanic. I know some Volkswagen cars cannot be bled at all without plugging the car into the appropriate computer.
 

KL2BE

New member
If the fluid is flushed without the DRBIII tool don't the remnants of the old fluid just get flushed into the system as the van is driven. Presumably if that is the case then regular maintenance will be adequate to maintain a satisfactory brake fluid condition?

Contamination of air in the brake system (the oxygen oxidizes the brake fluid and the water vapor is absorbed) occurs chiefly at the master cylinder reservoir; minorly at the air/cylinder interface at the master cylinder and calipers.
Contaminated fluid either migrates into the recesses of the ABS valving; or it does not :hmmm:. If it does, then a maintenace flush will dilute the contaminated fluid with fresh fluid. The delution should be minor given the relative volumes. If it does not migrate into those recesses, then the fluid there should never become contaminated :thinking:. Using this logic, the use of the DRBIII should be unnecessary :popcorn:.
What am I missing? :idunno: Is there another mechanism by which the brake fluid in the recesses is degraded? :thinking: And, if degraded, how can it do harm if it does not migrate to the calipers where it can heat-up and boil? :rolleyes:
I would use this kind of risk analysis: What are the odds that I will cause harm doing an incomplete DIY job versus the odds an ill trained or careless technician at a Chrysler Dealer will screw something up? :hmmm: So far in my life-experience, the odds of a screw-up at a Dealer Service Department are so high as to be verging on inevitable. :rant: Thank GOD for highly skilled independant shops like DR. A :thumbup:.
 

sikwan

06 T1N Can
Contamination of air in the brake system (the oxygen oxidizes the brake fluid and the water vapor is absorbed) occurs chiefly at the master cylinder reservoir; minorly at the air/cylinder interface at the master cylinder and calipers.
To add, there's also heat from braking that breaks the fluid down. Probably not as bad as the heat surrounding the clutch slave cylinder fluid in vehicles with a hydraulic clutch, but I know the section of fluid that is near the transmission/engine/slave cylinder comes out as a black sludge if not flushed periodically.

Contaminated fluid either migrates into the recesses of the ABS valving; or it does not :hmmm:. If it does, then a maintenace flush will dilute the contaminated fluid with fresh fluid. The delution should be minor given the relative volumes. If it does not migrate into those recesses, then the fluid there should never become contaminated :thinking:. Using this logic, the use of the DRBIII should be unnecessary.
I wonder if an accidental activation of the ABS should mix things as well. :smilewink:

Kind of like if you don't use your A/C, diesel fired heater, etc., seals start drying out. Use it or lose it.
 

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