Changing pads, bleeding fluid question...

[paranoidjack]

Guys, I just received a new set of pads from Joe. I was going to bleed all the brakes etc and do a full service. I remember reading in previous posts not to attempt to bleed the brake system without bleeding the ABS reservoir, but in the FSM it makes no mention of bleeding the ABS reservoir, only to bleed at the calipers and move along.

Can anyone offer some insight before I do this tomorrow? Thanks!

[maxnix]

I believe on the G50 Q45tech has said (or perhaps I read it somewhere else) that if a Consult is not used to activate the ABS pump, then the fluid in the ABS reservoir is not exchanged.

[paranoidjack]

I believe on the G50 Q45tech has said (or perhaps I read it somewhere else) that if a Consult is not used to activate the ABS pump, then the fluid in the ABS reservoir is not exchanged.

1) ^^This also stand with y33's?2) If so, to clarify, I cannot change all brake fluids without a consult? I.e., no way to mechanically activate the pump, relays jump, etc....

Thanks.
Modified by paranoidjack at 4:15 PM 3/4/2008

[maxnix]

Seems like relays (when they fail) activate the pump. You could flush, go drive and get into the ABS, then flush again.

[paranoidjack]

Seems like relays (when they fail) activate the pump. You could flush, go drive and get into the ABS, then flush again.

Hmmm. Not a big fan of that method. But if that's what it is, so be it. I'd prefer a proper drain and fill.

[RAP]

Hmmm. Not a big fan of that method. But if that's what it is, so be it. I'd prefer a proper drain and fill.

If you have noticed there is not much help on your issue? I too have studied the FSM and the ABS system and argued my case here about weather there is fluid trapped within the actual ABS control unit. The FSM does not offer much help and simply said to bleed the brakes in the usual manner, for both, brake caliper and ABS unit replacement or for any time there is a need to bleed the brakes.

The FSM displays a rather vague diagram of the function of the ABS and fluid flow. The unit contains some a pressure pump and a series of electro mechanical valves that are activated upon a signal from any one of three points, each front wheel, ,and from both back wheels as they are two for one.

The electro mechanical valves are contained within that ABS unit that you see in the engine compartment. If a signal is received from any of the non turning wheels the valves are activated, fluid pressure is relieved from that wheel and fluid is absorbed by the pump to maintain pressure for re-activation when the offending wheel is once again turning normally or at the same rate as the others.

That's my take on the ABS system installed in our cars but as stated prior, there is not much help from the FSM as the recommended procedure for a ABS malfunction is to R & R the unit intact. After re-installation of the ABS unit just bleed the brakes in the usual manner. Meaning, two persons needed, fill the master cylinder, pump the brakes and open the bleeder valve at the wheels, or, use a brake bleeder device.

The Consult is used to activate the ABS unit to check if it is functioning properly.

Hopes this helps and not added confusion. In any event the brakes are designed to function normally with or without a functioning ABS. Furthermore if you are an alert and aware driver you should not drive into any slippery conditions that will cause some device to activate and interfere with the brakes. No argument against test track results as they are under controlled and deliberate conditions.

Maybe more than you wanted but in any event, good luck.

Jack

[StarPD]

Interesting subject.When I bought my '05 Q45, I had ALL fluids flushed/replaced, including the brake fluid, at my Infiniti dealer.

Does anyone know if standard Infiniti dealer practice takes the ABS into consideration when they flush the brake system? Obviously, they have a CONSULT, so if one is needed to do a COMPLETE flush, they'd be equipped.

Thoughts on this?

[qship96]

I wouldnt assume the Infiniti dealer, or any other service provider to do anything but the most basic, fastest way to accomplish any task, unless customer requests, pays for, and inspects what they expect.Radiator flushes,transmission fluid changes,etc are just dump and fill 1x if you are lucky.

Regarding the brake fluid,I believe if it is changed frequently that the issue with any fluid being held up in the ABS system isnt a big concern due to the fact regular changes will mean most of the fluid in system will be new and dry, pulling any moisture in the small amount of old fluid stuck in abs until the moisture is equalised throughout the entire quantity of brake fluid in the system

[maxnix]

Regarding the brake fluid,I believe if it is changed frequently that the issue with any fluid being held up in the ABS system isnt a big concern due to the fact regular changes will mean most of the fluid in system will be new and dry, pulling any moisture in the small amount of old fluid stuck in abs until the moisture is equalised throughout the entire quantity of brake fluid in the system

Yes, but Dennis has noted that ABS units' seals fail because of acidic conversion of brake fluid by moisture and oxidation. So by inference, if the ABS is not recycled regularly by drivers, then the old fluid accumulate in the accumulator which leads to its demise.

Dennis, what does T-3 do when they bleed the brakes? Is the ABS pump activated while performing the fluid replacement, or is the old fluid left in the accumulator?

[qship96]

I am under the impression the ABS cycles during the self test every time the car is started and put in reverse? You can feel and hear it whirring,at least in my 96

[paranoidjack]

Regarding the brake fluid,I believe if it is changed frequently that the issue with any fluid being held up in the ABS system isnt a big concern due to the fact regular changes will mean most of the fluid in system will be new and dry, pulling any moisture in the small amount of old fluid stuck in abs until the moisture is equalised throughout the entire quantity of brake fluid in the system

This is assuming as Brian said that you semi-regularly activate the ABS to get this going. This isn't too easy to do on a regular basis without tearing up brakes and tires, neither of which I'm looking to accelerate the depreciation of.

Maybe the time to do it is when there is snow on the ground! I could use the ABS 10x by the end of my street!

One way or another I refuse to bleed a partial system, in my opinion a waste of time.

All or nothing....wait, did I say that? I meant "All" or "All."

Most importantly, I'm looking to do this in one clean shot. I don't have time to revisit this short of the next replacement, and I don't trust handing it over to anyone unless I am in the bay watching....and at that point, why pay someone else to do it?!?!

The time to drive to the dealer, wait, watch, and drive home, would be 2x what it would take me to do it alone. Unless of course, I can't do it at all without a CONSULT to activate the pump.

Per what was said above I will be sure to check whether the ABS pump exchanges fluids at startup. That would make life easy.

[frosti108]

lol @ title. i think thats what happens when my gf has her period

[Denver90Q]

Whenever, I go to Brakes Plus I always get the brake flush. Not sure exactly what is involved but it is only about $40 I think. The ABS pump on my 1990 failed many years ago and when I took it apart there was alot of corrosion in the plungers and I live in a fairly dry climate. I have yet to rebuild my calipers but I probably should check them for corrosion. The brakes on the 1990 are somewhat grabby whereas the 1995's have a smoother more linear feel? Don't think its the rotors because they were recently replaced.

[xerexabante]

+1 LOL

[Q45tech]

On ABS, TCS without bleeder valves before we acquired the BG Brake Bleeder system we use to crack the hard lines and bleed each one.On the Full cost flush 2 people for 30 minutes is a hour add on to standard.

Messy with fluid everywhere that need to be spray cleanered off or the paint melted.

The Consult won't test ABS you need a special $5000 ABS tester.

[maxnix]

This is assuming as Brian said that you semi-regularly activate the ABS to get this going. This isn't too easy to do on a regular basis without tearing up brakes and tires, neither of which I'm looking to accelerate the depreciation of.

On the contrary, ABS will limit flat spotting the tires. There is no extra wear and tear on the brake system by activating it. Be careful with the VLSD in snow though.

[paranoidjack]

On ABS, TCS without bleeder valves before we acquired the BG Brake Bleeder system we use to crack the hard lines and bleed each one.On the Full cost flush 2 people for 30 minutes is a hour add on to standard.

Messy with fluid everywhere that need to be spray cleanered off or the paint melted.

The Consult won't test ABS you need a special $5000 ABS tester.

Tech-so are you saying then, I DO need to bleed the ABS pump as well as the lines at the calipers? Or I'm good at the calipers only? y33

[bullittandy]

Sorry I don't know about the mechanics of the ABS pump but....

How much fluid could POSSIBLY be left in the pump? Bleed the brakes normally and the activate the ABS at your next drive. You'll have replaced at least 95% (being conservative) of the fluid.

[paranoidjack]

GREAT.

So I do the right side, bleed everything, A-OK, get to the driver side front, upper caliper slide is seized solid, pad was worn crooked, relatively new brembo rotor is gouged and damaged.....

Can't get the caliper slide out. Fighting with it now, but I fear it will be damaged by the time it comes out.

[maxnix]

Accck! No high temperature lubrication?

[paranoidjack]

Accck! No high temperature lubrication?

Ack, must have forgotten it on this slide last time.

It's out now. I'll probably replace it anyway but cleaned out the channels, lubes and moves just fine now.

Just reading up on brake break-in procedure and good to go...I will still have to order new rotors asap since one of the existing is gouged to hell. Hopefully the pad won't follow suit within the next week.

[maxnix]

Hopefully the pad won't follow suit within the next week.

Yes it will, but not too badly in a short time. Can you wait until someone air ships? Is the other rotor new?

If not, replace both pairs. Be sure to adjust your emergency brake before you put the wheels on.

[paranoidjack]

Yes it will, but not too badly in a short time. Can you wait until someone air ships? Is the other rotor new?

If not, replace both pairs. Be sure to adjust your emergency brake before you put the wheels on.

All 4 rotors were new about 25k ago, and are in great shape except the front left where the slide seized and the pad wore VERY unevenly (finally gave strong pulsating and I replaced the pads-not expecting to find the rotor).

I'll order another rotor and slide (lubed up but still not perfect tomorrow and replace when they come in; it will be fine.

[Q45tech]

Experience has show that 25k is a long time for pin lubricant to survive!

The original design with very soft pads needed rebuilding every 19-22k.

Harder pads may actually increase the pin temperature making the problem worse. Why I returned to oem pads after experimenting with longer wear aftermarkets.

Seems the G35/M45 are having same difficulty?