Problem Bleeding Brakes

[James]

I can get you one today IF IT EVER STOPS RAINING!!!!!

[Rush]

Thanks, James!
My mom said it's just been SO rainy there! They're in Channel Islands & it's just been miserable, I guess.

[bertvorgon]

Raining here also, winter does not want to end!

[Rush]

Ugh. We're due for yet ANOTHER foot of snow tonight! We have 10' snow banks around our house. I guess on the bright side, it's a good time to be camped out in the garage snuggled up to the wood stove & working.

[iceman510]

Can't vouch for operation, because I have not bled these lines yet, but I believe them to be correct.


Yours look good from the master to switch, and the LF line, but can't tell the destination for the other lines.

brake switch small 1.jpg (200.13 KiB) Viewed 139 times

brake lines 2.jpg (178.25 KiB) Viewed 139 times

[Rush]

Thanks, Iceman! Yours look the same as mine (except way nicer! lol!). Hmmm.

Here's a pic I found while digging through endless forum posts. The guy says it's a barn find, so potentially unmolested? The rear port on the switch in his goes into the front reservoir and the front port goes to the rear reservoir. Perhaps it doesn't even matter & I'm just chasing my tail here...

[Rush]

I made new lines this evening and now I have some pressure! Yay! Still not in working order, but I think it's a start. I started at the driver's rear after I bled the MC once the new lines were on, I almost immediately got air & fluid out. I have fluid to both front calipers but still can't use the bleeders. They must require way more pressure than is in the system right now or something. The pedal feels like it has "something" but definitely not right.

I guess once I'm sure air isn't my problem I might have to turn the the BMC. Maybe it's shot; I don't know what the symptoms of that are.

[datzenmike]

Most if not all masters are marked Front and Rear on the outputs. The first piston to be actuated on the master is the rear (closest to the pedal) going to the front brakes. When this travels far enough it begins to activate the forward piston applying the rear brakes. You definitely do not want these reversed either at the master or the brake warning switch. Applying the rears first would be a disaster as weight shifts forward off the rear tires lessening traction and locking them more easily.

[Rush]

My master is marked but the warning switch has no markings other than Nabco. Is there a way to be certain which is which on the switch? (ha! Rhymes)

[Rush]

Now that I'm looking at it, with the switch oriented with the end port facing the firewall like it is, I wonder if the line from the FRONT reservoir should go in the bottom port closest to the firewall since the end port and the upper port at that end are for the front brakes.

[gooned]

Yeah if you go back to Iceman’s pic, you are not the same on that.

Been way too long so I can’t verify.

[iceman510]

You appear to have switched the order of the two lines you made new that enter the switch from the bottom, as they are different from your earlier picture if I am seeing it correctly. Interesting that you are having better success.

Maybe it makes no difference, as I have never examined the passage routing in that switch housing.

As I mentioned in a previous post, I have not bled anything as I still have to make a new long rear underbody line, so I cannot vouch for functionality. I followed the manual and the original lines for my assembly. Previous project owner had made some new versions, but had used bubble flare line so I had to redo them anyway. I do still have all the originals in a pile here somewhere.

[Rush]

You're exactly right, Iceman. I was mulling over what Mike mentioned about how the MC plunger works (engages the front brakes first, then rear) in my sleep last night and I think now I understand how the whole program works. It seems as though all lines associated with the front (or the back) brakes need to go in their "half" of that valve. If that's the case, the lines I just made are incorrect and the stock lines were correct but the lines going into the upper ports were incorrect (I've since switched them).

Long saga short, I think I just had the upper lines on incorrectly but I've run in so many circles now, I can't remember. lol! So if I put the stock lines back on, with the switched upper lines, I think that may be the ticket.

While this all might seem like a colossal waste of time, it really isn't because I gained an understanding of how the system works (if this corrects the problem).

I'm sure that reads like word salad, sorry about that! But this is kinda what I mean.


We'll find out this afternoon, after I get brake fluid all over the place for the 1000th time this morning. Did I mention that I hate brake fluid? It's squeaky and it smells weird!

[iceman510]

Your last diagram makes sense with your comments about the front/rear lines grouped by side.

[Rush]

Whew! Lol!