Author |
Message |
Ian Johnston
Goo Roo South Australia UZZ30 GT 4.0, UZZ31, BMW R1150R
Posts: 1188 Reg: 07-2005
| I changed to TT brakes about 4 years ago, and could never quite get a good brake pedal feel after a manual bleed. I have got used to it, but wondered if there is a trick to bleeding them, or does someone know of anyone in Adelaide who has the correct tools to do it? My local Toyota dealer is of no help, saying that the Toyota ABS tool wont work on the Lexus system. ( I know, it is a Toyota, try telling my dealer!!) |
Peter Nitschke
Junk Filterer South Australia UZZ30 UZZ31
Posts: 11376 Reg: 11-2004
| I don't mind having a go at it with you. Also, try activating the ABS, eg braking on loose gravel as it supposedly helps by pumping fluid through the ABS system. Then bleed it again. |
Boris Siljanoski
TryHard Western Australia Soarer GZ20 TT
Posts: 353 Reg: 11-2007
| I wonder what Scan tools they used over in Japan to do it then? Surely there has to be some available. |
Christian Somerville
TryHard South Australia UZZ31 V8 LTD
Posts: 334 Reg: 03-2009
| Ian I am in the process of converting to TT brakes, any tips on that? |
Peter Nitschke
Junk Filterer South Australia UZZ30 UZZ31
Posts: 11377 Reg: 11-2004
| Christian, it's pretty straight forward. Get new copper washers for the brake lines though. |
Ian Johnston
Goo Roo South Australia UZZ30 GT 4.0, UZZ31, BMW R1150R
Posts: 1190 Reg: 07-2005
| The Bendix rep I used to deal with in my truck days suggested the ABS kick method, and it brings the pedal up for a while if activated on gravel. Just need to rebleed straight away. Christian, just try not to loose too much fluid when changing calipers. Thats what pappened to mine. Thanks for the offer Peter, I may have to come back up, and see what happens |
Boris Siljanoski
TryHard Western Australia Soarer GZ20 TT
Posts: 360 Reg: 11-2007
| Ian explain more about this kick method for bleeding ABS systems and how it works? |
Ian Johnston
Goo Roo South Australia UZZ30 GT 4.0, UZZ31, BMW R1150R
Posts: 1195 Reg: 07-2005
| Basically as Peter has said, you jam on the brakes on a gravel road, which then gets the ABS working, which then moves the brake fluid thru the system, hopefully taking some of the trapped air with it. Then re bleed the brakes. Maybe do this several times to get the air out of the ABS module. Because I had the calipers off for a while, the ABS module bled out, so when I re bled it, air is trapped in the module, which can only move if the ABS is activated. The correct scan tool will open the ports and make it easier to bleed, but it seems nobody has one to suit the Soarer system. Long winded reply, but hope it explains something. |
Boris Siljanoski
TryHard Western Australia Soarer GZ20 TT
Posts: 362 Reg: 11-2007
| Thanks, Wouldn't Toyota/Lexus dealers have this tool? Otherwise how would they do it? Would it be possibly to buy this tool from Toyota as a genuine item? |
Ian Johnston
Goo Roo South Australia UZZ30 GT 4.0, UZZ31, BMW R1150R
Posts: 1196 Reg: 07-2005
| My local Toyota dealer wasnt too helpfull, but Lexus dealer may have tools. I would have to go to the city for that. |
Dan McColl
Goo Roo Victoria (The Nazi State) Active V8 and the Beast.
Posts: 2360 Reg: 07-2005
| Another thing that can work is to crack the lines where they go into/come out of the abs unit slightly whilst someone pumps the pedal. This can sometimes get any trapped air out. |
Boris Siljanoski
TryHard Western Australia Soarer GZ20 TT
Posts: 469 Reg: 11-2007
| Now I don't know much about ABS systems hopefully somebody can clear this up for me I'm wondering how can trapped air in the ABS unit make for a spongy feel when during normal braking when ABS doesn't activate the ABS, so it's is not being used, so only fluid is being pushed toward the caliper not air because the air is trapped in the ABS unit? Because if the ABS unit is normally isolated from the rest of the system, wouldn't the only use for a scan tool be to open the valves so you can do a complete fluid change? If anybody can understand what I'm trying to say. |
Peter Nitschke
Junk Filterer South Australia UZZ30 UZZ31
Posts: 11427 Reg: 11-2004
| The fluid would be running through the ABS all the time, but it only kicks in when needed, so air trapped will affect pedal feel. It isn't a side circuit that then gets added when needed. Consider that the ABS effectively forces your foot off the brake momentarily to allow traction to be briefly regained. So fluid goes through it all the time, but it interrupts the pressure in pulses when it is activated. |
Boris Siljanoski
TryHard Western Australia Soarer GZ20 TT
Posts: 471 Reg: 11-2007
| Is there a diagram somewhere showing all the ABS lines and where they goto? Also like i said before, if the air is trapped in the ABS unit, even assuming that fluid still flows through, this trapped air doesn't reach the caliper as it's trapped, so how could it cause a spongy pedal feel. Because isn't the reason why you get a spongy pedal feel when air is compressed at the caliper, and the air has to be compressed first before the fluid can reach and push the piston in? So if the air is trapped in the ABS unit, how could it cause the brakes to feel spongy as that air isn't getting to the caliper? |
Peter Nitschke
Junk Filterer South Australia UZZ30 UZZ31
Posts: 11428 Reg: 11-2004
| Boris, it doesn't matter where the air is, it causes the same issue in that it is compressible. |
Boris Siljanoski
TryHard Western Australia Soarer GZ20 TT
Posts: 473 Reg: 11-2007
| I guess then is there some sort of way to trick the ABS System into cycling, is there some sort of way to fool the ABS Sensors into thinking there is a loss of traction while the car is on the jacks? Or take it for a drive, and let the ABS System cycle itself by losing traction or hard braking which does sound dangerous, then bleed. Repeat a few times? |
Peter Nitschke
Junk Filterer South Australia UZZ30 UZZ31
Posts: 11433 Reg: 11-2004
| I believe there are special tools, but not available. Use a loose surface, eg gravel on the side of the road, so you won't need to be going so fast nor have to brake so harshly. |
Boris Siljanoski
TryHard Western Australia Soarer GZ20 TT
Posts: 476 Reg: 11-2007
| For scan tools, which scan tool would say Toyota in Japan use? Surely they must have a way of doing it. |