Zetascry

Hey guys,

I recently powder coated all 4 calipers and they look amazing 🤩 - the calipers had to be removed and left for a week - in the process the vehicle lost all the brake fluid..

few questions -

1- is this bad for no brake fluid in the reservoir or lines? Car has been off and on jack stands and never started since

2- I’ve bought replacement banjo copper bolt gaskets - do I need two up from on either side of banjo bolts? They are brembo 6 pistons up front and single dual piston rears

3- can i ceramic coat the calipers after applying the brembo decal stickers?

4- what’s the process on tech stream to bleed the fluid? As usual air bleed or another option?

I will throw up some photos soon - they make this car look good .. guess the color lol many thanks again

sha4000

iTrader: (1)

Before you removed the callipers you should have pumped your brake and held it, then clamped the rubber brake line. This would have prevented sure from getting into the system. Once all your fluid leaked out it can be real difficult to bleed the brakes and you might have to do it several times before all the air is out. The worst part is that you most likely have air in the actuator if you let the master cylinder get empty.

Zetascry

it’s happened already and now I have to move forward in the right manner - did not want to damage the lines and they are steel brake lines idk how to clamp those without breaking them- I do believe there is a method to purge air and willing to flush multiple times to get it right - actuator has not been run while calipers off as stated above vehicle has been off entire time - thank you for your input.

yyymmm31

Sha4000 is right. You should not have let the brake fluid totally drain out. Now, with a drained-out brake actuator, it is much more time consuming to revive your brake system. To revive your brake system, you need to use the "Actuator has been removed" procedure (see attached file) and Techstream (preferably version 16.x or 17.x). Caution: (1) This special bleeding procedure consumes a lot of battery power. Before you performa this special bleeding procedure, you need to charge your car battery to the full level, and attach a good charger to your car battery to maintain sufficient power supply while performing this bleeding procedure. (2) This special bleeding procedure requires a reliable OBD2 connection. The cheap MINI VCI USB connectors often fail when bleeding the rear right brake (which also bleeds the brake actuator - the key step for you to revive your brake system). If your OBD2 connection fails while bleeding the right rear brake line (and the brake actuator), it will be a challenging process to revive your brake system. So, be extra careful here. If you are not familiar with using Techstream on LS460 brake system, read this thread to gain some knowledge about using Techstream on LS460 brake system and familiarize yourself with the Techstream screenshots: Tutorial LS460: Clear “Brake Malfunction, Check VSC System” Dash Error Messages - ClubLexus - Lexus Forum Discussion.

Zetascry

BB9

1- Yes, it is bad to have entire brake system to sit dry. Possibility of starting corrosion somewhere or contaminate it in some other way is pretty high.
2- You need two gaskets on each banjo bolt. One between the head of the bolt and the line and one between the line and the caliper body.
3- Not sure if ceramic coat will make that much of the difference in that particular application.
4- I believe there's a process in the techstream for the replacing of the actuator. Since you let all fluid out and the system is dry you need to use "actuator replacement" procedure to allow it to be bled completely and avoid damaging the actuator. Shouldn't be that much of a deal.

Zetascry

Thank you for the response - short and to the point! Will do

Zetascry

So I’m able to successfully “reset memory” and “Linear Valve Offset” but anytime I try to do zero down or air bleed procedure I’m getting an error - could this be due to low battery voltage ?

swfla

iTrader: (1)

If I remember correctly, the proper Lexus procedure is to have a battery charger on the car while doing a full brake bleed. So, yes to answer your question.

Zetascry

Actually had the parking brake disengaged - which is now solved on issue of zero down procedure. will do the brake flush as instructed and get back - maybe this will help others who are not as well informed about letting actuator run dry or when removing calipers from vehicle

Zetascry

thanks for the quick reply - I did connect a battery charger - will let it stay charging for 2 hours and then tackle the brake flush

Zetascry

I’ve followed this procedure according to the pdf text - I’m able to do all procedures- when o zero down the car beeps rapidly - then once off I’ve removed the accumulator connectors - turned off ecb - then done the front bleeding manually, which triggers the rapid beeping all again and I get the check brake message - once done with the front I reconnect the acummulator up and try the accumulator has been removed option but it fails once to the right rear caliper - in the pdf it states acummulator pressure must be 0.5 v to start air bleed but ever time I zero down , the car beeps - I turn off the car and once I turn it back on the accumulator is already building pressure and raising Its voltage

sorry for all this jumble but I’m confused as to what I may be doing wrong? For some reason accumulator won’t stay 0.5 v

should I reset memory and do a linear valve calibration before all this?

battery of vehicle is under current charge at 13.4V - is that too low?

yyymmm31

It is a challenge to demonstrate how to do it without being on site, but I'll try. No, don't do the reset memory and linear valve calibration before bleeding the brakes. The reset memory and do a linear valve calibration are part of this "Actuator has been removed" bleeding procedure, which you will need to do at the very end of the "actuator removed" bleeding procedure. From your description, it sounds that you successfully performed the bleeding of the two front brake lines but could not get through to bleed the RR brake line. I am assuming that you are using a reliable OBD2 VCI/connector (cheap OBD2 VCI's often run into problem when bleeding the RR brake line). Using Techstream version 16.x or 17.x, after charging your battery to the full level and connecting a good charger to the battery, re-do the "Actuator has been removed" bleeding procedure. Please follow the instruction on the computer screen. When there is a discrepancy between the on-screen instruction and paper instruction (the PDF file), follow the instruction on screen. Since you have successfully bled your two front brake lines, you don't have to actually bleed the two front bakes again. Just dry-run the steps of front brake bleeding. You should be able to complete the "Actuator has been removed" bleeding procedure. Again, I am assuming that you are using a quality OBD2 VCI/connector and Techstream version 16.x or 17.x.
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Zetascry

using tech stream 17 and a really good almost oem Vci connector - do I just click through the first part of the actuator bleed steps until to the right rear line or actually do them as In Disconnect the pump and actuator plug then turn off and wait 2 min etc? But not flushing the fronts? even with this almost oem vci I get a failed message - is battery voltage low? Had it connected up for few days - went from 13.4 v to 12.3 V after taking off charger - btw I successfully did the air bleed and got plenty of air out and with no messages on dashboard or tech stream - do I really need the actuator bleed process or can I just drive now? 🥲

yyymmm31

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Glad that you have Techstream version 17.x and a quality VCI connector. When I conducted the "Actuator has been removed" procedure, I faithfully followed every step on the computer screen, except that I dry-ran the bleeding of the two front brake lines (because I had already done it manually). So, if the computer screen instructs you to wait 2 minutes, do as instructed, even though the waiting may not seem to be important or meaningful. Having sufficient power supply is essential for completing this bleeding process. If you can, attach a charger to your battery that can provide up to 20A power current while you bleed the brakes. Do not open or close your car doors during the bleeding process. Regarding your question if you really need to complete the "Actuator has been removed" bleeding procedure, as a perfectionist, if I were you, I'd do it by the book, which is to complete the "Actuator has been removed" bleeding procedure. Lexus shop manual says that this is the method to purge out the air in the accumulator assembly after the brake actuator is removed or change (brake fluid ran dry in your case). If you would like to drive around after you completed "Usual air bleeding", I'd suggest that you do a couple of zero downs and individually bleed RR line before driving around as a temporary solution. To do so, after each zero down, use the "Usual air bleeding" procedure to bleed RR line (select the single brake line bleeding option to bleed RR line only), until you don't see any air bubbles coming out RR line. In the "Actuator has been removed" bleeding procedure, bleeding RR line also bleeds the actuator. The hope here is that by doing a couple of individual RR line bleedings after zero downs, you would purge out most of the air from the brake actuator. Please thoroughly test out your brakes before taking the car on the road. Again, this is only a temporary solution.
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