Alfa Romeo Forums banner

801 - 820 of 1045 Posts

·
Push hard and live
Joined
·
8,922 Posts
Discussion Starter #801
Just got back from picking up a temporary tag, and insurance card. I can drive it on the road.

Also, first full-tank fill up. Oooops. A couple of pin-holes appeared. I've patched them, after defueling. Hopefully my epoxy patch will hold.

I tried a pair of 60F9 idle jets for the trip to the fuel station. Not happy. I've popped back in the 50F9s that we installed initially. I was hoping to try some 55F9s, but those aren't in my box. I may go diddling about among the F8s and other oddities later. Next will be to do a full test with it all the way up to operating temp. I've got a borrowed AFM that'll use in the not too distant future. Don't really want to burn holes in anything.
 

·
Registered
Joined
·
3,681 Posts
For your prestige license plate, I suspect that "GRIGIO BIACCA" may be a little too long. How about? "TOURING" or "TANGO"

Mark
 

·
Push hard and live
Joined
·
8,922 Posts
Discussion Starter #803
Hmmm. Too late. I like the “Tango” idea. However, I snapped up “Veloce1” that just came available from a de-regged Alfa.
 

·
Registered
Joined
·
199 Posts
Exciting times! 🙂. Bet you cant wait to go for a proper run.
I remember very well my first proper run in the 2600, a warm spring day driving through Avebury here in the UK after 5 years of hard work. It felt amazing that I was finally able to drive the car and that it was driving so well, then I got scared as the car was approx 20miles from the tool box 😅
 

·
Registered
Joined
·
11,646 Posts
Hmmm. Too late. I like the “Tango” idea. However, I snapped up “Veloce1” that just came available from a de-regged Alfa.
Which of course makes we wonder what happened to the other Alfa to cause de-registering??? ... :(

Hopefully it was a relatively modern common one!
Pete
 

·
Push hard and live
Joined
·
8,922 Posts
Discussion Starter #806
Been tweaking brakes. I can drive the car, but not to the panic-stops-are-ok stage. I’m certain it’s the rear brakes having too much play, but the adjusters go from loose to locked up in 1/4 turn.

The 50F9 idle jets are working well when warmed up. Time to see what the AFR says.

I’m going to scrounge some weights and get the front end aligned. Probably Wednesday.

Still a tiny vibration in the driveline. I think.

Trans with NS behaving perfectly.
 

·
Push hard and live
Joined
·
8,922 Posts
Discussion Starter #807
Grim news

Today, I decided to pop in the passenger seat and give my son a ride. Got the pan in place, and.....

No bottom cushion or seat back. Huh?!

I’ve been over the property, nooks and crannies, five times. Bottom cushion and seat back are not here.

Two possibilities.... 1) at Johnny’s, the upholstere. 2). When I pointed to a pile and asked my grandson to “take those empty boxes down to the street for trash pickup tomorrow.” Emphasis on “empty”.

I’ll check with Johnny tomorrow.

Here’s a challenge...

My son and I did more brake tweaking today. I had the nose up on ramps. Upon completion, I checked the pedal and it was firm and high.

Took the car down, and for a test drive. Whoa... barely any pedal, just as before.

That’s twice a nose high attitude gave me great pedal, which was gone when leveled out. I’ll repeat the experiment a third time just to confirm it’s not the 70’s acting up again.

What dark magic could this be?
 

·
Registered
Joined
·
199 Posts
DP. I had this exact same problem with my brakes. I put approx 7L of fluid through the lines. I tried gravity bleeding power bleeding, classic pedal opp bleading, jacking up the front jacking up the rear, tapping calipers and m/c, held pedal down with length of wood for a week etc. I tried everything, and although I had s brake pedal it wasnt very good.
I decided in the end just to drive around carefully for a while and every now and again pumping up the brake pedal, sometimes it went to the floor and other times I was almost launched across the hood!
After a while (approx 400 miles) it must have bled itself as the brakes are now very good and I never have a soft pedal.
 

·
Registered
Joined
·
7,346 Posts
Check ALL your hard line fittings again with pressure on the pedal. Did you bench bleed the master?.. I can't remember.. I'd power bleed one more time and not use more tha a 1/2 reservoir of fluid.
 

·
Push hard and live
Joined
·
8,922 Posts
Discussion Starter #811
We have no leaks at any joint. Reservoir has remained full for the better part of a month since last efforts at bleeding.

I did “bench bleed” the master, but that is an imprecise art.

I reset the free play, but it was close.

Yet, for all you wizards out there.... why would the pedal be firm with the front up on ramps, and with no pumping, yet immediately low when returned to level?

Anyone have a seat back and bottom cushion I can acquire? Otherwise, my plans for Concordia are dashed.
 

·
Registered
Joined
·
7,346 Posts
My theory is you have an air bubble in the master when you raise the nose he bubble rises to the nose of the master past the outlet going to the rear brakes. When you lower the nose the bubble migrates back toward the outlet port of the master just like a bubble in a carpenter's level.. There is no other explanation. Power bleeding will cure that in 10 minutes.

Sorry about the seats.. I guarantee you they didn't end up in the trash. They are under your bed.
 

·
Registered
Joined
·
14 Posts
I purchased from retro rosso the complete springs for the seats. Now looking for the tubolar frame or will rebuilt. Very difficult to find them.

Sent from my SM-N950W using Tapatalk
 

·
Push hard and live
Joined
·
8,922 Posts
Discussion Starter #814
Divot...

Not sure if you’ve explored the inner workings of this particular master cylinder. It’s also found in 750s and 101s.

The first is simple physics. The liquid is essentially incompressible. Any air is compressible. Where the air is in a closed system isn’t a factor. Until the air is compressed to the pressure equal to other areas of resistance in that system, the liquid will transmit little to no force. So, a bubble could be anywhere in the compressed system and have the same result.

In these master cylinders the reservoir return port is a hole drilled in the piston. If that hole is forward of what I’ll call the “master pressure seal”, then pedal motion will simply force fluid back up to the reservoir. Once pedal motion moves the hole past the pressure seal, it blocks off the reservoir return, and pressure is transmitted to the wheel cylinders. So, whether an air bubble is touching the return hole isn’t a factor, per se. if the hole is inside or outside the seal matters.

The spec calls for a small amount of pedal freeplay. I’ve confirmed that. However, I note that the first motion of the pedal generates a fluid pulse into the reservoir. That may be correct, but we’d like the least possible throw before closing off the return port. I may try to dial out any excess travel before port closure and see what that gets.

This master cylinder is using a piston supposedly made in Australia by the folks that did Dogga Dave’s brakes. They made some big mistakes in the rest of his system, so I must wonder if they drilled the return hole too far forward on the piston. The previous master cylinder I was using is one I overhauled, but I don’t recall if I used an original piston or an aftermarket piston from the UK. If the latter, and if it was also mis-drilled, it could explain the similar excess travel before pressure is generated.

But why does nose-up factor? Or, have I done something else while the noose is up which would give good pedal upon first application?
 

·
Registered
Joined
·
11,646 Posts
Have you tried bleeding while the nose is up on the ramp?

It has to be an air bubble hiding in the system somewhere and somehow (even as I type this I'm doubting what I am typing) it ends up in a better place when the front is in the air.
Pete
 

·
Registered
Joined
·
7,346 Posts
Don, i don't know what a fluid pulse is . The reservoir serves two purposes as I know it. A reserve for any leaks in the system and expansion vessel when and if the fluid in the system heats up. You raised a flag on the positioning of the plunger holes from past experience....something ain't right in there. Technically, you could seal it off in a static state (Some cars aperated that way with brake failures killing people), I suppose, because you don't need more or less fluid in the system. .I've bled brakes with vigorous pedal cycles and nary a ripple in the reservoir was ever observed. it sounds like you have bigger fish to fry so I'll stay out of this conundrum. Good luck going forward.
 

·
Push hard and live
Joined
·
8,922 Posts
Discussion Starter #817
Divot,

No complaints about suggestions at all. We all learn. Hopefully.

The "fluid pulse" is seen when someone depresses the pedal, and brake fluid splashes upwards out of the open reservoir. I don't recall at this moment if the pulse is seen on depression, or release. That could tell us something.

Although the "auto-adjust" brakes are not discussed in any Alfa literature I've seen (except maybe a vaguely recalled 2000 Sprint supplement that I can't find), I just found a note in one of the service manuals that tells us to back out the adjusters on the front wheels all the way before bleeding. OK. Haven't tried that. However, during previous tests I have clamped off the rear brake hose and instantly had high and firm pedal, leaving me to think the problem is isolated to the rear somehow. I may also try backing out the rear adjusters as part of another go at all of this.

But, as you note, there could be something odd about the master cylinder(s) that I've tried. Both overhauled, not leaking, and holding pressure. As noted, with the rear hose clamped off, good, high, firm pedal is available.

I keep thinking it's something adjustable in the rear, but I'll be da^^ned if I can find it.
 

·
Premium Member
Joined
·
171 Posts
What happens if you put the back end on ramps? If lifting the front end eliminates the symptoms, and level moves a bubble into an "active area" (Assuming that's what is actually happening), maybe raising the back will be worst case, but best orientation for pushing the bubble to an exit.
 

·
Registered
Joined
·
30 Posts
I had a similar experience on my 1960 Land Rover, which has a similar vintage Girling system. After replacing every hydraulic component (all cylinders, lines and hoses) during a full mechanical restoration and attempting every known bleeding technique, nothing had changed - partial pedal on the first pump, but decent pedal on the second pump. Finally, I had the drums turned and everything was instantly perfect - full hard pedal on the first pump. After 35 years of marginal braking, it was a good day and the best $40 I ever spent.

Because the drums were out of round, the adjusters had to be backed off to the point where most of the fluid displaced by the master was needed to take up all the slack. Doesn't address your nose-up phenomenon, but may be worth a try.
 

·
Registered
Joined
·
11,646 Posts
I drove an early Land Rover once ... never again ... went straight through a compulsory stop because, even though I was pushing on the brake pedal for all my worth, I could not stop the thing. In fact it hardly seemed to be loosing any speed at all. Scared me silly.

Pete
 
801 - 820 of 1045 Posts
Top