Bleeding Brakes. Remove the reservoir cap sensor mesh screen ?

[sugarwood]

I'm going to try bleeding my brakes with this Harbor Freight bleeder and my air compressor.
Incidentally, has anyone used this kit ?



The actual directions say to use 90psi, but the forums all say to use 10psi. Stick with 10psi to play it safe?
I will use DOT 4 fluid.

The kit comes with an auto fill bottle that you just hang upside down into the reservoir. To hang the bottle, the kit comes with a few different mounting clamps that hang off the sides of the reservoir cap opening. This way, you don't need a helper constantly topping off the reservoir. In the photo, you can see the hooked contraption on top of the thin fill bottle. The bottle hangs upside down into the reservoir.

However, my fluid reservoir has the cap with a floating sensor. It's not just a standard cap opening. In the photo, you can see the metal prong attached to a mesh screen. Is there a way to remove this? It you try to unscrew it, it just spins in place. Since the mesh is blocking the opening, the upside-down fill bottle won't get submerged into the fluid. Thanks for any help!

[TRE Cup]

with your fingernails pry on the mesh cup lip and the entire screen will come out with the float. Careful not to overfill the reservoir , after you complete the brake flush/bleed. Reinstall the float /screen assembly

[dad911]

That does not look like a pressure bleeder to me. I think they are using a larger volume of air from compressor, passing over an orifice to create a (weak) vacuum.

I predict it is not one of HFs better tools

Do not pressurize your reservoir to 90 LBS!

[Tidybuoy]

I agree, 90psi is ok at the bleeder valve to create suction but if you are actually pressurizing your brake system, 10psi is plenty. Double that and you could pop your reservoir.

One word of advice, make sure you cover your paint at the reservoir. It only takes a tiny bit of brake fluid to ruin a paint job. Even vapors will do damage. If you don't have a service cover, a large blanket will work.

[sugarwood]

Originally Posted by TRE Cup

with your fingernails pry on the mesh cup lip and the entire screen will come out with the float. Careful not to overfill the reservoir , after you complete the brake flush/bleed. Reinstall the float /screen assembly

Ok, so you're saying that entire inner cup does, in fact, come out.

Originally Posted by dad911

That does not look like a pressure bleeder to me. I think they are using a larger volume of air from compressor, passing over an orifice to create a (weak) vacuum.

I predict it is not one of HFs better tools

It got a ton of positive reviews, so I was willing to try it.
I will report back my results.

[sugarwood]

I read a few other threads where people forgot to "clamp off the overflow hose"
Anyone know where or what this is?

[dad911]

I don't believe you need to crimp overflow. It is not a pressure bleeder. According to the reviews, the canister with the trigger goes at the caliper end, you hook up the lines, and when you pull the trigger it generates a vacuum and pulls out the brake fluid.

I probably wouldn't screw around with the auto fill, just have someone watch the master cylinder and add fluid when it gets low.

The overflow is under the carpet. I'm pretty sure in the pic you posted, it is towards the lower right, by the bump in the reservoir.

[Tidybuoy]

The overflow is a tiny tube that comes out of the side of the master cylinder reservoir. On my '74 it is hidden by the trunk carpet so a novice won't see it right away and get really frustrated (ask me how I know).

You won't need to pinch this off with your setup as you are basically pulling out fluid via vacuum at the bleeders. In a pressure bleed system, you pressurize the master cylinder reservoir and that pushes out the fluid. Without the overflow clamped shut, you will pump and pump and nothing will happen.

[sugarwood]

Yes, here is the tube. Anyone know where this goes? On mine, the green hose loops back around and turns into that braided black hose clipped to the top of the reservoir. I'm not sure where it goes after that.

In any case, so if you're pressure pushing from the reservoir, you need to pinch off that side overflow hose.
Otherwise, all the fluid just goes into the rabbit hole of the green overflow hose.

But, if you're pulling from the caliper bleed screw, you're fine. Thanks for clearing that up...

[sugarwood]

Bumping to retry this aborted project.
I still have no idea how to remove that mesh screen from the reservoir.
I was unable to pry it off. I even tried to use pliers to grab it, but it would not budge. It only would spin in circles.
Is there a special trick?

Incidentally, The HF pressure bleeder was junk. I tried it on a different car.
It kept injecting air bubbles as it sucked fluid from the bottle.
Took me a long time to figure out it wasn't due to air in the lines...
I tossed it in the garbage and will just do the 911 by hand with a helper.

[Bill Jennings]

sugarwood,
I just did a fluid change and my set up looks the same as yours.
I used a clean pair of needle nose pliars gently on one of the ribs and the whole mesh screen pulled right out.
I couldn't get my nail under the lip or grab it with my fingers.
I would clean up the top area before you pull the screen so no dirt falls in as well.
Cheers
Bill

[sugarwood]

Ok, I'll try that now.

BTW, that grime on the "deck" of the reservoir is totally hardened remnants of fluid.
I have wiped that area down as best as I could. Those are more like stains.

[DRACO A5OG]

Yeap, the infamouse ATE Blue fluid, nice but it stains the reservoir. I stopped using that stuff. I use GOLD. When it comes out clear, that is your new fluid

Break a Leg brother and be very very careful with the fluid on your paint. Wipe off immediately.

[sugarwood]

Bill, I was able to pop off the mesh dish using the needlenose. Thanks.

DRACO, if I never said it, an explicit thank you for your sustained help with all my silly noob questions.

I will use a different color to know when I am flushed.
How much brake fluid will I need for a full flush?
Got any suggestions on what to buy?

I have an unopened bottle of this in the garage, can I use it?
http://www.autozone.com/brake-and-power-steering-fluid-additives/brake-fluid/valvoline-32-oz-dot-3-and-4-brake-fluid/33406_0_0/

[DRACO A5OG]

ATE Gold is recommended to handle the heat the brakes generate. You can get it at most performance shops or our HOST :-)

Valvoline Dot 3/4 is good for standard cars but with all the work you are putting into her try to locate the ATE Gold or even better the Nissan's Endless RF650, probably one of the best but pricey.

1 Can will do you just fine. Most of the old fluid will come out of the right rear, where you are starting

Take your time and watch the fluid level.

[HarryD]

FWIW. Vacuum bleeding is tricky. You have to get a good seal at the bleeder nipple or you get bubbles which may or may not come from the caliper or lines.

I no longer use this method.

[DRACO A5OG]

Use some di-electric grease or Syl-glide around the nipple and it will help keep the air out or use zip ties.

[puddy]

I'd recommend gravity bleeding them, it's super easy and cheap. If you search on here you find the procedure. You can do it while your working on other things. Basically get a small length of clear pvc hose, find something to hold the hose straight up so that the fluid can flow u close to the height of the fluid resevior. I used some flexible wire around the hose and created a hook that grabbed the trunk hinge. Crack the bleeder screw open and let gravity do the work. The level of fluid will slowly rise in the tube over the course of 5 minutes or so and then when you see no more bubbles coming up close the bleeder screw and empty the hose and move to the next caliper. I did this for the first time a couple months ago and wished I'd known about it years ago!

[Mervo]

I always used gravity bleeding. I have also used a low pressure bleeder with the correct cap, but never more than 10psi (and the vent clamped) or you may blow the connections from the lines from the reservoir to the MC. Both approaches work, depending on the time you have available.

Gravity Bleeding: How?

[Bill Jennings]

Sugarwood,
I used a Gunsen pressure bleeder which is quick and easy.
It has the correct cap for the reservoir and you take the pressure from a tyre at 10psi.
I just kept checking fluid level in the reservoir I didn't use the supplied bottle for the fluid as there is less to cleanup.
I used to use the gravity method but prefer to get the job done quickly.
Use whatever method you are comfortable with.
Cheers
Bill