How-To: Bleed brakes with ForScan

[MauiRoads]

I appreciate you. But, alas, I still think I’m communicating poorly.

I will definitely bleed all four corners. But then, when I do the ABS cycle, is it enough to just run the FORSCAN cycle via opening just one of the caliper bleeders? Seems like any air in the ABS would clear using one caliper ….

In my one-time experience: Using FORScan ABS bleed and Master Cylinder bleed functions does a complete system bleeding through all four calipers.

I think that even though FORScan uses the ABS pump to do an individual caliper bleed, it does not also activate the ABS bleed function and bleed the ABS module. I guess if you're trying to save brake fluid, you can just bleed one or more individual calipers, but then you won't have bled the master cylinder or the ABS module. And since you're supposed to use a pressure bleeder for any FORScan bleed function, you've already put a lot of fluid in the pressure bleeder.

Based on my one-time FORScan (European version with individual components) bleed, in the future, I will probably work top-down again: Master cylinder bleed and then ABS bleed. Both of those functions bleed all the way through all four calipers. Yes, that's a repeat-bleed of the lines from the ABS to the calipers, but if the Master bleed or ABS bleed releases air or contaminants, it won't come out of the system unless it bleeds all the way through to a caliper. I guess you could save fluid if the Master and ABS bleed functions could bleed just through the left front caliper. But it doesn't offer that function, and then to fully bleed the whole system, you'd still have to bleed the other three calipers individually.

On the other hand, if you know that the system is good, and you only replace a caliper or line, you can just use the individual caliper bleed function for that corner.

 

[cidsamuth]

In my one-time experience: Using FORScan ABS bleed and Master Cylinder bleed functions does a complete system bleeding through all four calipers.

I think that even though FORScan uses the ABS pump to do an individual caliper bleed, it does not also activate the ABS bleed function and bleed the ABS module. I guess if you're trying to save brake fluid, you can just bleed one or more individual calipers, but then you won't have bled the master cylinder or the ABS module. And since you're supposed to use a pressure bleeder for any FORScan bleed function, you've already put a lot of fluid in the pressure bleeder.

Based on my one-time FORScan (European version with individual components) bleed, in the future, I will probably work top-down again: Master cylinder bleed and then ABS bleed. Both of those functions bleed all the way through all four calipers. Yes, that's a repeat-bleed of the lines from the ABS to the calipers, but if the Master bleed or ABS bleed releases air or contaminants, it won't come out of the system unless it bleeds all the way through to a caliper. I guess you could save fluid if the Master and ABS bleed functions could bleed just through the left front caliper. But it doesn't offer that function, and then to fully bleed the whole system, you'd still have to bleed the other three calipers individually.

On the other hand, if you know that the system is good, and you only replace a caliper or line, you can just use the individual caliper bleed function for that corner.

Okay . . . so when you use the ABS procedure, you'll open up both rear caliper bleeders at the same time, then repeat the procedure with both fronts?

 

[MauiRoads]

Okay . . . so when you use the ABS procedure, you'll open up both rear caliper bleeders at the same time, then repeat the procedure with both fronts?

When bleeding the ABS module or the master cylinder, FORScan instructs you to open both front caliper bleeders, and when finished with that part, then instructs you to open both rear bleeders at the same time. If you have them, it's easiest with two 11mm wrenches for the front and two 8mm wrenches for the rear, and have a bleeder bottle already set up on each front caliper, then move them to each each rear caliper...so that you can quickly open and close both bleeders..

 

[cidsamuth]

When bleeding the ABS module or the master cylinder, FORScan instructs you to open both front caliper bleeders, and when finished with that part, then instructs you to open both rear bleeders at the same time. If you have them, it's easiest with two 11mm wrenches for the front and two 8mm wrenches for the rear, and have a bleeder bottle already set up on each front caliper, then move them to each each rear caliper...so that you can quickly open and close both bleeders..

Thanks, will give it a go.

 

[NATYPE]

Do we know if the independent component targeting for these procedures was integrated into the current release? Bounced through the changelog and couldn't quite tell.

 

[MauiRoads]

Do we know if the independent component targeting for these procedures was integrated into the current release? Bounced through the changelog and couldn't quite tell.

I haven't downloaded the latest release. I'm afraid that if I do, and it doesn't have the features of the "European" version that FORScan provided me, I'll never get them back

 

[jivenene]

This seems to be the most complete thread on using ForScan for flushing brakes. Couple questions remain:

1) Does conventional pressure bleeding flush the fluid out of the ABS? If yes, then is Forscan necessary? If no, is it a big deal if it is possibly only a few ml?
2) Does the latest FS release 2.3.66 bleed each corner seperately for USDM cars? Or do we still not have access to the EU brake tools?
3) How much total fluid is needed for the procedure? I only have 1QT of the good stuff....

I will be attempting this soon, trying to be prepared, I don't like surprises lol.

thx!

PS, I've spoken to you at Maui C&C a couple years ago, but just moved to SoCal. Hope all is well!

 

[Dialcaliper]

This seems to be the most complete thread on using ForScan for flushing brakes. Couple questions remain:

1) Does conventional pressure bleeding flush the fluid out of the ABS? If yes, then is Forscan necessary? If no, is it a big deal if it is possibly only a few ml?
2) Does the latest FS release 2.3.66 bleed each corner seperately for USDM cars? Or do we still not have access to the EU brake tools?
3) How much total fluid is needed for the procedure? I only have 1QT of the good stuff....

I will be attempting this soon, trying to be prepared, I don't like surprises lol.

thx!

PS, I've spoken to you at Maui C&C a couple years ago, but just moved to SoCal. Hope all is well!

A couple answers best I can tell:

1) I was unable to really get any fluid movement just with the pressure bleeder. Maybe could have done it with pedal + pressure bleeder but didn’t really get it to work.

2) Yes the latest releases let you bleed a single corner, but it’s not apparent until you try it. When you initiate the bleed sequence, you tell it which “component” you replaced. There’s a “brake fluid” bleed option that does all corners (both rears together, then both fronts together). If you select that you replaced a caliper, brake hose, etc, it asks which corner and only bleeds that corner. Many of the other options (master, abs unit, etc) just run the same as the bleed sequence.

3) For a full solid flush and bleed including the clutch, I’d guess it took about 1.5 qts. Do the clutch first (manual pressure bleed) before doing the brakes. After bleeding everything I realized I hadn’t done the clutch, so I did it then ran the bleed again and used almost 2 liters.

If you just run the bleed once and don’t try to fully flush the system by doing the sequence multiple times, you might be able to skate by with a liter of fluid.

You can do the thing where you put fluid only into the car and not the pressure bleeder tank, but it’s really annoying. Much less effort to put the brake fluid into the tank and then just clean it out afterwards with 90% isopropyl alcohol.

 

[M-Sport fan]

If you've already had a brake flush done, and just want to do another clutch fluid flush with a different (higher temp/racing/slightly more viscous) fluid to better handle the heat and possibly prevent the whole slave cylinder pedal on the floor problem/symptom (which could potentially be worse with the much thinner fluid??), that fluid will never reach the ABS (and traction control/ESC) module, being that it is only reaching the 'spillway' and the reservoir, correct??

 

[Dialcaliper]

If you've already had a brake flush done, and just want to do another clutch fluid flush with a different (higher temp/racing/slightly more viscous) fluid to better handle the heat and possibly prevent the whole slave cylinder pedal on the floor problem/symptom (which could potentially be worse with the much thinner fluid??), that fluid will never reach the ABS (and traction control/ESC) module, being that it is only reaching the 'spillway' and the reservoir, correct??

I suppose you could try, but it’s hard to believe that will remain that way long term - I’d imagine that you’d eventually get slow diffusion through the system every time brakes/clutch get actuated and even if it’s not complete mixing, you’ll get some crosstalk between the two.

It sounds like your slave cylinder is failing and you’re just trying to limp along until it’s worth pulling the transmission to change the clutch?

 

[M-Sport fan]

It sounds like your slave cylinder is failing and you’re just trying to limp along until it’s worth pulling the transmission to change the clutch?

It is really hard to say, since in most cases, from most on here, once they have one single pedal stuck to the floor occurrence, it only keeps getting worse and worse until they cannot even lift the pedal with their foot (or hand) anymore.

Mine ONLY ever sticks to the floor in very hot ambient temps, after much stop and go traffic, and then it acts perfectly fine once the temps drop back down below the upper 80s and 90s.
Hence why I want to try more viscous/more racing like higher temp fluid in the clutch hydraulics, exclusively.

It has been doing this for the last 3 years or so, every summer, and it is not every single time even under those torrid conditions.
Wouldn't it have gone completely by now if it was failing due to leakage past the seals or a fully worn, scored cylinder wall??

Yes, I would rather NOT change all of the co$tly but not worn out yet, 'while I'm in there paying for the labor anyway' other stuff right now if it is not necessary, given there are only 49K miles on the car currently.

(I'd rather put that coin into the suspension, or a 'safe' tune now, or save it for the insane $$$$ timing belt/water pump debacle near 100K miles.)