NNBS brake job done - pedal not firm

[4WDTRK]

Finally did a full brake job (front and rear) with new calipers, rotors, pads, and stainless braided hoses (all six). The fronts got changed to the larger 07+ calipers/rotors.

I bled the entire system refilling with fresh fluid. Test driving does not feel firm like I was expecting. I'm thinking a second bleed is probably necessary after driving and seating the pads. Must still be some air in the system. Anyone have any experience with this? Thanks!

 

[MassHoe04]

Was the fluid checked and topped off to the proper level (if needed) after working the brakes some? If the pads hang up, they can keep the pistons from extending. Then when the pads finally seat, the pistons extend further than they did before, dropping the fluid level in the reservoir.

I did not have a power bleeder when I did mine. I just pumped the pedal to build pressure, then opened the bleed valve. The first time was soft, but after a few more repeats of the pump and bleed... Pedal feel improved. Felt fine to me after that. Brakes work great.

I would go through the process of working the brakes in. A few good stomps on the pedal to seat everything real good. Then, check the fluid level and top of it more is needed in the reservoir.

 

[4WDTRK]

Everything was topped up, but in my case I didn't touch the pedal until after the bleed. I did the rear axle, bleed, and test drive, then the front axle the next day.

I have a feeling things will improve after another 4 corner bleed.

 

[corvette744]

Everything was topped up, but in my case I didn't touch the pedal until after the bleed. I did the rear axle, bleed, and test drive, then the front axle the next day.

I have a feeling things will improve after another 4 corner ble

Everything was topped up, but in my case I didn't touch the pedal until after the bleed. I did the rear axle, bleed, and test drive, then the front axle the next day.

I have a feeling things will improve after another 4 corner bleed.

You definitely have air in the system.Especially with new stainless lines it will feel so much harder than the rubber junk.Keep bleeding possible you will have to activate the abs pump if air is stuck in their.I would also pressure test the system and make sure nothing is seeping.

 

[4WDTRK]

Yea it's not even close to feeling 'hard'. The power bleeder essentially does a pressure test at 15psi, I've checked all fittings several times and all look good. Might not be able to bleed until end of the week. I'll report back. Thanks!

 

[89Suburban]

Find a slick dirt or gravel road you can slam the brakes on and make the ABS kick on and cycle a few times then try 4 corner bleeding again.

 

[4WDTRK]

I really don't think I got air in the ABS module, but you never know. Slamming the brakes in the dirt sounds like fun though!

 

[89Suburban]

I really don't think I got air in the ABS module, but you never know. Slamming the brakes in the dirt sounds like fun though!

One other thing to note FWIW. If you have high mileage worn rear the axle shafts move in and out and that causes the rear calipers to spread open some requiring a double pump to bring pedal back up to where you expect it.

 

[rockola1971]

You cant bleed the brakes on our K chassis the old way like we did in the 70-80's. You must have a bi directional scanner like the Tech II to actuate the valving in the ABS valvebody. There are solenoid valves that have to be actuated in order to get all the air out that is upstream and downstream of the ABS Valve body. The Tech II actually has one man Brake Bleed function built in. Its great and works awesome too! It uses the ABS system to pump the brakes for you. Ive been across this bridge before and its the reason why I bought my Tech II clone years ago.

 

[4WDTRK]

You cant bleed the brakes on our K chassis the old way like we did in the 70-80's. You must have a bi directional scanner like the Tech II to actuate the valving in the ABS valvebody. There are solenoid valves that have to be actuated in order to get all the air out that is upstream and downstream of the ABS Valve body. The Tech II actually has one man Brake Bleed function built in. Its great and works awesome too! It uses the ABS system to pump the brakes for you. Ive been across this bridge before and its the reason why I bought my Tech II clone years ago.

Good info thanks! Would this tool only be necessary if air somehow got into the ABS module or part of the ABS was serviced? For hose and caliper changes shouldn't I be good to go?

 

[Blackcar]

If I'm reading your post right, I start with front driver side first then move to pass front then rear etc.

 

[wjburken]

If I'm reading your post right, I start with front driver side first then move to pass front then rear etc.

Typically I start with the wheel furthest from the master cylinder and move closer. Right rear, left rear, right front, left front.

 

[rockola1971]

Good info thanks! Would this tool only be necessary if air somehow got into the ABS module or part of the ABS was serviced? For hose and caliper changes shouldn't I be good to go?

You know the passage through the hoses from the calipers leads straight to the ABS valve body, right? If you disconnected a caliper and that line drained substantially then you have air up to your valve body and the first time you drove it an pressed on the brakes you cycled fluid into brake lines that have air in them. Depending on the volume of brake fluid drained originally will determine how long you fight this. It can get better by locking up the brakes and actuating the ABS and then trying the traditional bleeding that you are doing but the brake feel will not ever be right and you will be bleeding it until you are blue in the face and still not get it right. Ive been down this road. I got the brakes to the point where it was "safe" to drive and then ordered a clone Tech II and performed the built in brake bleed function and it took less than 15mins. The Tech II clones are cheap on aliexpress.. You can get a setup for around $300 and it will do alot. You can even turn one fuel injector off at a time for testing with the Tech II. Its awesome!

 

[4WDTRK]

You know the passage through the hoses from the calipers leads straight to the ABS valve body, right? If you disconnected a caliper and that line drained substantially then you have air up to your valve body and the first time you drove it an pressed on the brakes you cycled fluid into brake lines that have air in them. Depending on the volume of brake fluid drained originally will determine how long you fight this. It can get better by locking up the brakes and actuating the ABS and then trying the traditional bleeding that you are doing but the brake feel will not ever be right and you will be bleeding it until you are blue in the face and still not get it right. Ive been down this road. I got the brakes to the point where it was "safe" to drive and then ordered a clone Tech II and performed the built in brake bleed function and it took less than 15mins. The Tech II clones are cheap on aliexpress.. You can get a setup for around $300 and it will do alot. You can even turn one fuel injector off at a time for testing with the Tech II. Its awesome!

Great info! For the amount I would actually use a tech II I don't think I'd get my money's worth. I'm just gonna call my mechanic and get it to them for a bleed and be done with it. Thanks again!

 

[MassHoe04]

Great info! For the amount I would actually use a tech II I don't think I'd get my money's worth. I'm just gonna call my mechanic and get it to them for a bleed and be done with it. Thanks again!

I don't always like dropping cash for things that don't get used, but I did some of my own quick math...

I spent about $330 to get mine (about $250 + 1 week shipping from overseas).

Repair shop rates average $80 - $100 per hour.
Most shops charge 1 hour minimum.
Diagnostic fees, $150 (often waved, but only if they find something to repair and do the work - which is often more than 1 hour labor...)

Then add in things I mis-diagnose, buying parts I don't need and buying other parts I do need to finally fix the issue.

If I decide one part should fix an issue, buy it and the issue is not fixed. I'm in for the cost of the part + my time.
If I figure it has to be this other part, put that in and issue is not fixed... I'm in for cost of 2 parts + my time.
If I finally cave and bring it to the shop... I am in for 2 parts that didn't fix it, my time, at least $150 for diagnostic fees, any additional labor and any additional parts to actually fix it.

I may need help from the guys on the forum on some of the more in-depth functions of the Tech 2, but having it will allow me to dive in to individual sensor functions and diagnostic testing. If I can prevent myself from buying one extra part and avoid a total of 2 hours of shop labor... My Tech 2 will have paid for itself. $330 spent now has a very good chance of saving many times that amount over the next several years.

Nobody is forcing a Tech 2 on anyone, but from what I have seen and heard on the forum... Diagnosis and repair success rates are pretty convincing for people with Tech 2. If you are going to DIY the majority of work, it seems like the cost of a Tech 2 has great potential savings in time, money and aggravation.

I have not had to use my Tech 2 just yet, but I am ready and feel fairly confident it will be able to get me out of trouble some day. I'll be ready.

 

[4WDTRK]

I don't always like dropping cash for things that don't get used, but I did some of my own quick math...

I spent about $330 to get mine (about $250 + 1 week shipping from overseas).

Repair shop rates average $80 - $100 per hour.
Most shops charge 1 hour minimum.
Diagnostic fees, $150 (often waved, but only if they find something to repair and do the work - which is often more than 1 hour labor...)

Then add in things I mis-diagnose, buying parts I don't need and buying other parts I do need to finally fix the issue.

If I decide one part should fix an issue, buy it and the issue is not fixed. I'm in for the cost of the part + my time.
If I figure it has to be this other part, put that in and issue is not fixed... I'm in for cost of 2 parts + my time.
If I finally cave and bring it to the shop... I am in for 2 parts that didn't fix it, my time, at least $150 for diagnostic fees, any additional labor and any additional parts to actually fix it.

I may need help from the guys on the forum on some of the more in-depth functions of the Tech 2, but having it will allow me to dive in to individual sensor functions and diagnostic testing. If I can prevent myself from buying one extra part and avoid a total of 2 hours of shop labor... My Tech 2 will have paid for itself. $330 spent now has a very good chance of saving many times that amount over the next several years.

Nobody is forcing a Tech 2 on anyone, but from what I have seen and heard on the forum... Diagnosis and repair success rates are pretty convincing for people with Tech 2. If you are going to DIY the majority of work, it seems like the cost of a Tech 2 has great potential savings in time, money and aggravation.

I have not had to use my Tech 2 just yet, but I am ready and feel fairly confident it will be able to get me out of trouble some day. I'll be ready.

Again great info and I'm all for it! In this case I'm also in a bit of a time pinch and need my rig up and running asap. I may honestly look into one down the road though.

Another after thought... this issue may have been avoided by simply capping the disconnected hard lines with rubber vacuum caps. Would have saved mess and probably kept air from getting too far up the system.

 

[Joseph Garcia]

Use a Tech 2 once to avoid taking your truck to the shop, and the Tech 2 probably already paid for itself. My Tech 2 has paid for itself many times over at this point.

 

[Tonyrodz]

Have you checked the Tech 2 members location thread? Might be someone close to you that has one they can let you use, or to give you a hand.

 

[MassHoe04]

Again great info and I'm all for it! In this case I'm also in a bit of a time pinch and need my rig up and running asap. I may honestly look into one down the road though.

Another after thought... this issue may have been avoided by simply capping the disconnected hard lines with rubber vacuum caps. Would have saved mess and probably kept air from getting too far up the system.

I've found myself in similar situations... I can totally relate! Tech 2 on a someday wishlist might be good to keep in mind for later.

On brakes:

When I did my rear calipers, I had the reservoir cap off (just resting on top for protection). I did one side at a time. While getting the rotor, pads and caliper situated on that side, I topped-off the reservoir to the very top and left the brake line disconnected from the caliper until I was ready to bleed.

I think I actually did a good thing for myself, even if I didn't really realize it at the time!

With the line disconnected while I worked on getting the other components assembled, fluid continued to drip into the catch pan below.
I work slow, so I kept checking the fluid in the reservoir and ended up topping-off a couple of times to keep it full to the brim.

When the other parts were in place, I then attached the line and bled.

What I might have done, even if unintentionally, was have gravity slowly and continuously flow fluid downstream from the reservoir to the open end of the line.

I think that did a couple of helpful things for me:
1) Prevented the Master Cylinder and booster from running dry (always full while the work was being done).
2) The slow, steady flow of fluid through the line under gravity prevented air from coming back into the line.
3) Provided a bit of a flush on the potentially dirty line even before attaching to my nice clean caliper.

Aside from the normal manual (one-person) bleed at the caliper, I didn't have to do anything. Pedal feel was great! Brakes worked as expected. No issues with ABS.

Like I said, I may have just done things they way I did them, without knowing I may have done something to my advantage for a change.

 

[4WDTRK]

Just ordered the damn scan tool lol! My mechanic says what I did should not have put air into the ABS system. I'm going to do a second bleed myself and figured why not just use the tool?