BN1 Brake Pedal Hitting The Downpipe

[homebeforedark]

Hello All,
I'm helping a friend get his BN1 on the road. The brake pedal hits the downpipe about 1 1/2" before going to the floor. Is this normal?

 

[Bob_Spidell]

The clutch pedal on our BN2 hits the downpipe when fully depressed. It's not normal; I think many, if not all, of the newer downpipes are malformed (they should go straight down farther before bending to the rear). However, if your brake pedal is hitting the downpipe either the pipe is seriously malformed or you have some air in the brake lines.

 

[busybrit]

As you can see the clutch peddle has been depressed the brake hasn't.
They move along way and when the original down pipe, has only one, is fitted there's not much room between the metal peddle sealing plate and the pipe.
You can see the upper edge of the plate has been bent, because it touched the down pipe ? may be,.

 

[Bob_Spidell]

Nope. Something wrong with the brakes--they shouldn't go to the floor. If you haven't filled and bled the brake system yet I wouldn't worry about this; you should have at least half pedal--probably 2-3 inches, at least--travel left without hitting the floor.

 

[Bob_Spidell]

View attachment 40952As you can see the clutch peddle has been depressed the brake hasn't.
They move along way and when the original down pipe, has only one, is fitted there's not much room between the metal peddle sealing plate and the pipe.
You can see the upper edge of the plate has been bent, because it touched the down pipe ? may be,.

That's with the original downpipe? Now I don't feel so bad; but I'm not going to bend my sealing plate to prevent it. Considering using some ball-pein persuasion on the downpipe, though sometimes that can cause a 'ticking' noise in the exhaust. Have heard from others that some of the re-pop downpipes are incorrectly shaped, though.

BTW, the 100s came with a bracket from the engine to the downpipe; items# 8 & 9 on this page:

https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=28861&SortOrder=50

Our BN2 didn't have one when we got it; they're kind of a pain to install.

 

[drambuie]

Nope. Something wrong with the brakes--they shouldn't go to the floor. If you haven't filled and bled the brake system yet I wouldn't worry about this; you should have at least half pedal--probably 2-3 inches, at least--travel left without hitting the floor.

. I defiantly agree! Also, I would recommend converting to dot 5 brake fluid if you are doing a "complete" brake system rebuild. Best thing I ever did, no more eaten away rubber seals in my master cylinders and very good brake peddle pressure year after year!

 

[Bob_Spidell]

. I defiantly agree! Also, I would recommend converting to dot 5 brake fluid if you are doing a "complete" brake system rebuild. Best thing I ever did, no more eaten away rubber seals in my master cylinders and very good brake peddle pressure year after year!

Oh boy! Another brake fluid thread starting! I agree. Have had silicone fluid in my BJ8 for many years (over 20, probably), with nary a problem (but we installed it after a total system overhaul; new seals, etc.). I did have a 'foot valve' seal crack once, but it appeared to be a mechanical rather than chemical problem. Others report issues; Norman Nock first advocated DoT 5 then recanted when it leaked in a Jag he worked on, and I believe our own Randy F. had problems with it. OTOH, we put Castrol's finest in our BN2, and after the car sat for a couple years due to my father's illnesses the fluid gelled. Cleaned out the system and installed Pentosin DoT 4--I think it's what is used in BMWs--and it's been fine for several years.

 

[homebeforedark]

FWIW,I found that the brake pedal hits the downpipe while bleeding the brakes. But it hits the pipe while over two inches from the floor which is too close for comfort in my book. The clutch pedal will also hit about an inch from the floor. I'm going to order a mild steel downpipe on Monday and see if there is a difference.

 

[drambuie]

Oh boy! Another brake fluid thread starting! I agree. Have had silicone fluid in my BJ8 for many years (over 20, probably), with nary a problem (but we installed it after a total system overhaul; new seals, etc.). I did have a 'foot valve' seal crack once, but it appeared to be a mechanical rather than chemical problem. Others report issues; Norman Nock first advocated DoT 5 then recanted when it leaked in a Jag he worked on, and I believe our own Randy F. had problems with it. OTOH, we put Castrol's finest in our BN2, and after the car sat for a couple years due to my father's illnesses the fluid gelled. Cleaned out the system and installed Pentosin DoT 4--I think it's what is used in BMWs--and it's been fine for several years.

LOL...well, not really wanting to start back and forth regarding dot 5, I simply wanted to pass on my "personal" and practical experience using dot 5 brake fluid in my vintage British cars. For me it proved the right move because my Vintage car is used as a weekend driver and layed up most of the winter months and not used in the race circuit . It's been 5 years now and never any leaks or master/slave cylinder problems anymore and each and every season my brakes have great peddle pressure. Last summer I had 3 panic stop situations, one of them was a seedy looking kid in a old beat up mustang that actually tried to pull out in front of me to cause a deliberate accident... I slammed on the brakes and did a quick maneuver to avoid the little twit... Happend to me twice now in my Healey, I guess they think we Healey owners are all rich and want to collect a fast buck! When using dot 3 I always had to rebuild my master cylinders every 2 or three years and got very tired of it! Plus no more of that dot 3 destroying my paint work... In conclusion, I would definitely convert to dot 5 as standard practice on any future vintage car I use as a weekend driver. Ok...I will brace myself for the beat downs now...LOL

 

[Bob_Spidell]

You won't get a beat down from me. I think silicone/DoT 5 is the way to go. We put the DoT 4 in the BN2 because my dad had already bought some and he was more comfortable with 'stock.' Silicone BF is also non-flammable; it's not unheard-of for brake fluid to catch fire provided an ignition source (remember the Ford trucks--unfortunately we have one--that burned down some garages and homes when the cruise-control interrupter switch shorted, igniting DoT 3?).

Note that any silicone-based product--waxes, BF, ArmorAll, etc.--will cause fisheye in paint if not completely removed. I've heard the best way to remove all oils, greases and silicones before painting is to scub well with Dawn dishwashing soap and warm water.