Brake bleeding and fluid

[Phrede]

Going to be installing braided brake lines soon and thought it would be a good time to flush and bleed the system. Anyone have experience using either vacuum or pressure type bleeders? Recommendations or thoughts?

I've also read that using the TechII is also required (which I have) to run the ABS. Correct?

Anyone made the switch to DOT4 fluid? Thinking about Motul RBF600. I'm a big fan of synthetic fluids.

 

[Stella]

Going to be installing braided brake lines soon and thought it would be a good time to flush and bleed the system. Anyone have experience using either vacuum or pressure type bleeders? Recommendations or thoughts?

I've also read that using the TechII is also required (which I have) to run the ABS. Correct?

Anyone made the switch to DOT4 fluid? Thinking about Motul RBF600. I'm a big fan of synthetic fluids.

I do remember reading in the service manuals that a tech2 is required for bleeding of brakes. Probably to actuate the valves/solenoids in the abs.

Vacuum pumps work very well and make the bleeding process ALOT quicker. Which ever process you use should give you instructions. Just don't let your reservoirs get low air is your enemy.

Synthetics are great but they don't mix with factory fluids. Trying to get out all the old fluids and replacing with your fluid would waste ALOT. Guess it depends on how you plan on using the car. Tracking it alot maybe,street driving occasional ass whoopin I think factory is okay.

Those rotors you picked up are they DBA 5000 and 4000 rear. Been looking to go to a two piece for the great look. Found a place with really good pricing kns brakes. Only thing is the hat on the rotors I want are anodized red and would personally like black.

Sounds like your gonna have a whole new ride this year good luck with your projects!

 

[xlrlist01]

Going to be installing braided brake lines soon and thought it would be a good time to flush and bleed the system. Anyone have experience using either vacuum or pressure type bleeders? Recommendations or thoughts?

I've also read that using the TechII is also required (which I have) to run the ABS. Correct?

Anyone made the switch to DOT4 fluid? Thinking about Motul RBF600. I'm a big fan of synthetic fluids.

There is value in operating the foot pedal to bleed brakes as this action helps to clean the master cylinder bore in parts of the bore that otherwise do not get swept clear by normal brake pedal action.

Using unapproved brake fluid in the sophisticated systems as fitted to the XLR (and many other modern vehicles) raises all sorts of concerns. Racing fluids are very unsuitable for the systems designed for general road use. The valving in the XLR makes using synthetics extremely unwise unless you 100% certain that you can meet the characteristics required, so far as I am aware, no true synthetic meets the required specification (or even comes close). I have previously provided a link to a TRW product, see link below but I certainly do not recommend it.

Put simply, do not put a DOT 4 or 5 synthetic product in your XLR. Just maybe consider a DOT 4 ESP or 5.1 ESP if you are 100% certain it meets ALL the required specification, including viscosity, compressibility, air entrapment and component compatibility.

Note the description of your suggestion: "Description, Motul RBF600 is 100% synthetic polyglycol-based brake fluid exclusively designed for racing.", especially that word "exclusively". The braking system in the XLR is not designed for racing fluids, it is totally (and dangerously) unsuitable. That "RBF" stands for "Racing Brake Fluid".

The GM specification is DOT 3, I strongly recommend you stick with Cadillac's choice.

See https://www.xlr-net.com/forums/care-and-maintenance/7156-dealer-service-suggestions-no-trust-2.html

 

[Phrede]

I do remember reading in the service manuals that a tech2 is required for bleeding of brakes. Probably to actuate the valves/solenoids in the abs.

Vacuum pumps work very well and make the bleeding process ALOT quicker. Which ever process you use should give you instructions. Just don't let your reservoirs get low air is your enemy.

Synthetics are great but they don't mix with factory fluids. Trying to get out all the old fluids and replacing with your fluid would waste ALOT. Guess it depends on how you plan on using the car. Tracking it alot maybe,street driving occasional ass whoopin I think factory is okay.

Those rotors you picked up are they DBA 5000 and 4000 rear. Been looking to go to a two piece for the great look. Found a place with really good pricing kns brakes. Only thing is the hat on the rotors I want are anodized red and would personally like black.

Sounds like your gonna have a whole new ride this year good luck with your projects!

Yep, DBA 5000/4000 rotors from KNS. Very quick service.

 

[zeek]

Unless you are the type that really likes doing dirty jobs to save a few pennies......Just take it to your local Chevy dealer. I just had them flush and bleed out all the old brake fluid in my 08 Silverado with 170k on her. They only charged 90 bucks and it was well worth not having to deal with all that mess myself!

 

[Phrede]

Unless you are the type that really likes doing dirty jobs to save a few pennies......Just take it to your local Chevy dealer. I just had them flush and bleed out all the old brake fluid in my 08 Silverado with 170k on her. They only charged 90 bucks and it was well worth not having to deal with all that mess myself!

I much prefer doing my own maintenance for a number of reasons like knowing it was done right and spotting any potential problems early. This happens to be part of an upgrade a stealer will not do at any price.

Not sure I know what mess you're referring to. Yes, I'll get my hands dirty but that is about it.

 

[GM MUSL]

I have upgraded to stainless braided lines now on all 3 XLRs I have owned. The first 2 times I experienced trouble reinstalling the new lines and found this is a common problem well documented on the Corvette forum. There is a thought lines were "stripped" when installed at the factory and affects the rethreading of the lines onto the the solid lines at the chasis. This is only a problem getting started and avoideing cross threading. The "fix" filing threads as outlined by others I found was not the best solution. I did my latest install last week and doing it this way was completely trouble free.

When removing the brake lines disconnect at the caliper first and prepare for a little mess as the fluid drips. When disconnecting at the chasis line be sure to have a flare nut wrench for that end. You will find it easier if you remove the retaining bracket off the frame and push it back out of your way. As you loosen the flare nut from the line repeatedly loosen and tighten every turn. I found doing this 5 times each turn did the trick. Yes it sounds dumb but compared to the hours of grief fixing the "stripped" nut this is easy. I think the problem is corrosion on the flare nut and the threads need to be clean but doing this after the old line is removed did not work for me. Using the old line as a cleaner as you remove it worked.

 

[Phrede]

I have upgraded to stainless braided lines now on all 3 XLRs I have owned. The first 2 times I experienced trouble reinstalling the new lines and found this is a common problem well documented on the Corvette forum. There is a thought lines were "stripped" when installed at the factory and affects the rethreading of the lines onto the the solid lines at the chasis. This is only a problem getting started and avoideing cross threading. The "fix" filing threads as outlined by others I found was not the best solution. I did my latest install last week and doing it this way was completely trouble free.

When removing the brake lines disconnect at the caliper first and prepare for a little mess as the fluid drips. When disconnecting at the chasis line be sure to have a flare nut wrench for that end. You will find it easier if you remove the retaining bracket off the frame and push it back out of your way. As you loosen the flare nut from the line repeatedly loosen and tighten every turn. I found doing this 5 times each turn did the trick. Yes it sounds dumb but compared to the hours of grief fixing the "stripped" nut this is easy. I think the problem is corrosion on the flare nut and the threads need to be clean but doing this after the old line is removed did not work for me. Using the old line as a cleaner as you remove it worked.

Thanks for the tip! I'll be sure and "clear the threads" when removing the flex line fittings.

 

[MarkSki]

That's the same way of chasing threads with a tap. If you have some brake fluid to keep things wet that will help clean the junk out of the threads of the nut or a bolt.

 

[GM MUSL]

That's the same way of chasing threads with a tap. If you have some brake fluid to keep things wet that will help clean the junk out of the threads of the nut or a bolt.

That method did not work for me the last time I did the line replacement because the tap would not start easily due to the tapered thread and tended to cut more than just clean the existing thread.

 

[MarkSki]

That method did not work for me the last time I did the line replacement because the tap would not start easily due to the tapered thread and tended to cut more than just clean the existing thread.

What I was refering to was when you tap a hole to thread it, you use a little cutting fluid in the tap then start turning the tap in the hole. You take a turn or two in the back off to allow the metal shavings to be removed from the new thread, then you turn a little more creating more new threads until your finished.

In your case it sounds like you used the wrong tap. You tap's thread size was large than the already created thread and the threads per inch and pitch of the tap was wrong.

How did you correct your problem?

 

[GM MUSL]

What I was refering to was when you tap a hole to thread it, you use a little cutting fluid in the tap then start turning the tap in the hole. You take a turn or two in the back off to allow the metal shavings to be removed from the new thread, then you turn a little more creating more new threads until your finished.

In your case it sounds like you used the wrong tap. You tap's thread size was large than the already created thread and the threads per inch and pitch of the tap was wrong.

How did you correct your problem?

I mistakingly said tap when I meant die. The tapered end of the flare nut is the problem. I had the correct size die and even purchased a thread repair file but no luck. I eventually refiled the tapered end and forced the new line on and was lucky it did not cross thread. I had no trouble however this last time using the old line as a way to prevent the problem.