SE5a rebuild/rolling restoration - no brakes today

Discuss and exchange views and technical information about our cars.

Moderators: scimjim, Lukeyboy46, erikscimitardemon, Roger Pennington, philhoward

Post Reply
Jpwill7675
RSSOC Member
Posts: 35
Joined: Wed Aug 29, 2018 10:22 pm
Location: Dorchester, Dorset
Has thanked: 45 times

SE5a rebuild/rolling restoration - no brakes today

Post by Jpwill7675 » Wed Apr 03, 2019 4:13 pm

Thanks for the recent advice. I have now replaced the diff oil after removing part of the Watts linkage to get to the refill plug. I took the car for a 30 mile shake down yesterday. The car ran slightly roughly but without any major issue, leaks or drama. This morning I went to take the car for another run but nearly crashed into the gates - no brakes at all.

The pedal goes down to the floor without much resistance and pumping the brakes had no effect. Running the engine made no difference either. The vacuum hose from the servo to the engine looks intact. I have checked the system and can no see no obvious sign of leakage at the master cylinder, servo or lines to the calipers. The brake master cylinder was fitted two years ago and the car has only done about 1200 miles since then. I wonder if it is a coincidence or if I have knocked something whilst working on diff.

Could anyone suggest what I should check next. Thanks for your help.

Regards, Jim


SE5a Rolling restoration, Discovery daily driver, Triumph Tiger 800 fun, Cannondale Synapse fitness

User avatar
scimjim
RSSOC Member
Posts: 37043
Joined: Sun Oct 01, 2006 10:08 pm
Location: Gloucester
Has thanked: 122 times
Been thanked: 908 times

SE5a rebuild/rolling restoration - no brakes today

Post by scimjim » Wed Apr 03, 2019 4:17 pm

Are you losing fluid? you might be pumping fluid into the servo or out of the rear slave cylinders - or the master could just be U/S and not pumping?


Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), TI SS1 (snotty), 1600 SS1 (G97), 1600 SS1 (C686CCR), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

User avatar
philhoward
RSSOC Member
Posts: 24678
Joined: Tue Aug 29, 2006 5:41 pm
Location: Staffs, UK
Has thanked: 45 times
Been thanked: 579 times
Contact:

SE5a rebuild/rolling restoration - no brakes today

Post by philhoward » Wed Apr 03, 2019 4:29 pm

You can lose a lot out of a rear cylinder before it starts to become evident at the wheel..


Phil Howard
Scimitarweb Forum Admin
SS1 1600 Rooster Turbo; Sabre Mk1.5, Sabre Mk2
Previous: SE5/5a/SS1 No.1/SS1 Rooster/SS1 1800Ti/SE5a 24 Valve
http://www.ss1turbo.com
Never try and argue with an idiot. They drag you down to their level, then beat you based on experience.

User avatar
philhoward
RSSOC Member
Posts: 24678
Joined: Tue Aug 29, 2006 5:41 pm
Location: Staffs, UK
Has thanked: 45 times
Been thanked: 579 times
Contact:

SE5a rebuild/rolling restoration - no brakes today

Post by philhoward » Wed Apr 03, 2019 4:31 pm

Daft question - the clevis pin hasn't fallen out where the cylinder attaches to the pedal, has it? Normally if you lose one circuit of hydraulics, you still retain some braking from the unaffected circuit (although it might not feel like it).


Phil Howard
Scimitarweb Forum Admin
SS1 1600 Rooster Turbo; Sabre Mk1.5, Sabre Mk2
Previous: SE5/5a/SS1 No.1/SS1 Rooster/SS1 1800Ti/SE5a 24 Valve
http://www.ss1turbo.com
Never try and argue with an idiot. They drag you down to their level, then beat you based on experience.

Jpwill7675
RSSOC Member
Posts: 35
Joined: Wed Aug 29, 2018 10:22 pm
Location: Dorchester, Dorset
Has thanked: 45 times

SE5a rebuild/rolling restoration - no brakes today

Post by Jpwill7675 » Thu Apr 04, 2019 9:59 am

Thanks Jim & Phil for the suggestions. The fluid level is still on max in the reservoir and the master cylinder is quite new. I will check the rear cylinders today and also the clevis pin. If its just the pin that will be a result ( & a bit alarming)

Cheers, Jim


SE5a Rolling restoration, Discovery daily driver, Triumph Tiger 800 fun, Cannondale Synapse fitness

User avatar
Roger Pennington
RSSOC Member
Posts: 19780
Joined: Tue Aug 29, 2006 9:43 pm
Has thanked: 134 times
Been thanked: 498 times

SE5a rebuild/rolling restoration - no brakes today

Post by Roger Pennington » Thu Apr 04, 2019 7:41 pm

philhoward wrote:
Wed Apr 03, 2019 4:31 pm
Normally if you lose one circuit of hydraulics, you still retain some braking from the unaffected circuit (although it might not feel like it).
I didn't think the 5-series had dual circuit brakes?


....Roger

RSSOC member (since 1982)
- - - - - - - - - - - - - - - - -
Image

"Condition can be bought at any time; Originality, once lost, is gone forever" - Doug Nye

halfpenny
Posts: 211
Joined: Sat Jul 09, 2016 7:49 pm
Has thanked: 12 times
Been thanked: 13 times

SE5a rebuild/rolling restoration - no brakes today

Post by halfpenny » Thu Apr 04, 2019 7:50 pm

If the fluid remains on max, you don't have a leak. So either the master cylinder piston is not being pushed (pedal disconnected) or the piston seal is moving, but not sealing on the bore to allow pressure to be generated. Standard 5a is indeed single circuit.



User avatar
philhoward
RSSOC Member
Posts: 24678
Joined: Tue Aug 29, 2006 5:41 pm
Location: Staffs, UK
Has thanked: 45 times
Been thanked: 579 times
Contact:

SE5a rebuild/rolling restoration - no brakes today

Post by philhoward » Thu Apr 04, 2019 7:53 pm

Roger Pennington wrote:
Thu Apr 04, 2019 7:41 pm
philhoward wrote:
Wed Apr 03, 2019 4:31 pm
Normally if you lose one circuit of hydraulics, you still retain some braking from the unaffected circuit (although it might not feel like it).
I didn't think the 5-series had dual circuit brakes?
It doesn’t - I was having a blonde moment.. :oops:


Phil Howard
Scimitarweb Forum Admin
SS1 1600 Rooster Turbo; Sabre Mk1.5, Sabre Mk2
Previous: SE5/5a/SS1 No.1/SS1 Rooster/SS1 1800Ti/SE5a 24 Valve
http://www.ss1turbo.com
Never try and argue with an idiot. They drag you down to their level, then beat you based on experience.

Jpwill7675
RSSOC Member
Posts: 35
Joined: Wed Aug 29, 2018 10:22 pm
Location: Dorchester, Dorset
Has thanked: 45 times

SE5a rebuild/rolling restoration - no brakes today

Post by Jpwill7675 » Mon Apr 08, 2019 9:23 pm

Managed to get at the rear cylinders today. The brake pads were pretty ropey and it looks like the wheel cylinder was the culprit.
IMG_4065.JPG
IMG_4065.JPG (321.52 KiB) Viewed 594 times
I struggled to remove one of the solid brake pipes from the cylinder and will make up a new length from scratch. I am correct in thinking it should be 3/16 pipe into 3/8 UNF 24 male fitting?

Thanks in advance for your advice.

Regards, Jim
Attachments
IMG_4066.JPG
IMG_4066.JPG (269.23 KiB) Viewed 594 times


SE5a Rolling restoration, Discovery daily driver, Triumph Tiger 800 fun, Cannondale Synapse fitness

User avatar
philhoward
RSSOC Member
Posts: 24678
Joined: Tue Aug 29, 2006 5:41 pm
Location: Staffs, UK
Has thanked: 45 times
Been thanked: 579 times
Contact:

SE5a rebuild/rolling restoration - no brakes today

Post by philhoward » Tue Apr 09, 2019 6:04 am

The pipe is normal 3/16” - I think you’re right with the fitting too.


Phil Howard
Scimitarweb Forum Admin
SS1 1600 Rooster Turbo; Sabre Mk1.5, Sabre Mk2
Previous: SE5/5a/SS1 No.1/SS1 Rooster/SS1 1800Ti/SE5a 24 Valve
http://www.ss1turbo.com
Never try and argue with an idiot. They drag you down to their level, then beat you based on experience.

Post Reply

Return to “General Technical Discussion”