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rogerowen

Brake Servo advice please

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21 hours ago, Andy Moltu said:

The necessity for a catch tank is more about track use. If an engine blows and pressurises the crankcase you don't want to belch a pint or two of oil onto the track.

For road use the catch tank is less important.

That makes sense. Thanks. :)

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8 hours ago, Bfg said:

 

That makes sense. Thanks. :)

I get that - but what I'm looking for is an improvement to the standard PCV set up + installing a remote brake servo.

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Roger,   I respectfully wonder if others are being diverted from the wording of your original post, having taken a fancy to more bling in their engine bay, or otherwise being swayed by thoughts of racing set-ups ..most of which four cylinders are TR2 to TR4 which never had a PCV valve in the first place.?    

The PCV valve is designed to modulate inside crankcase air-pressure slightly lower than ambient air, whatever the altitude (within reason) and throughout the engine-speed range from just ticking over to full chat. The benefits of which I have written of previously. It achieves that surprisingly well considering it's such a simple and reliable device ..as long as it is periodically cleaned out, and the rubber parts (like any on a car) including the pipes are replaced every ten or fifteen years (..more frequently in hot dry climates or with very hard use).  And as has been mentioned previously - it does need to be mounted correctly so its crankcase breather pipe can drain its separated oil  'downhill all the way'  back into the rocker cover. 

So perhaps the question one might ask is "how did others fit a remote brake servo (..and keep their standard PCV valve setup) ?"  

 

In case you do not have a copy, the following references to Triumph's  (optional extra) MOT-A-Vac servo unit, from their workshop manual.  

P1320680.thumb.JPG.0c58a2694fba8f1e9e20cb4a2c770ba2.JPG

And because it was an optional extra that may be fitted retrospectively - the manual includes instructions for fitting the vacuum pipe to the inlet manifold. 

 P1320681.thumb.JPG.78477339e91876ee42b4c475bebf097a.JPG

This workshop manual is really not very good as the TR4A is, at best made, referenced to in supplements,  so the inlet manifold shown (in the photo above) is that of a TR4 rather than 4A. The later car doesn't have the 'cast-on boss'  referred to in this text,  but the 45 degree angle of that seems only to facilitate a more direct route for the vacuum pipe (so that the vacuum pipe doesn't point straight upwards and then kink because of the low bonnet line).  But the principle would be the same ; to drill and tap into the manifold midway across it ..and from that take the pipe (perhaps using a 45 or 90 degree elbow to point it in the right direct) to your remove servo unit.  Or if you don't want to drill and tap a new hole then (as has previously been suggested) simply use a Y or T piece from the breather pipe.   Note., should any part of the vacuum fail  (on the crankcase-breather side or the pipe to your servo) - you would not loose your brakes, only their servo assistance.

For reference here is a photo (courtesy of Jay B from Pennsylvania, on the Triumph Experience forum)  using a rather neat (small) catch tank before the PCV valve. 

02BFF1D9-90E3-4D2C-A738.thumb.jpg.0f2fb90f10c629267ce4d19f7387cdd0.jpg

He claims the catch tank works very well and no oil gets into the PCV valve.  Btw., the nipple on top of the catch tank is a dip stick and not a vent.  It is a closed circuit so the crankcase partial vacuum is maintained. 

Again I hope that helps,  Pete.

 

Edited by Bfg
..image didn't load, so try again

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Hi Pete,

I'm with you.

Hi Roger,

what are you afraid of?

Ciao, Marco

 

Edited by Z320

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Poor old Roger, who just wanted a simple way to fit an aftermarket brake servo is now into dismantling his inlet manifold and carbs, obtaining a tapping drill and special tap and unless he has a pillar drill then hoping he can drill and tap a true hole so the adaptor will fit and  seal. 
Many owners have forgotten the old mantra “KISS” ( keep it simple stupid)

The pros and cons of the various options open to Roger have been well documented in 3+ pages of posts with 3 or four setups suggested all of which would work but offer different levels of complexity and cost.  I won’t add anymore to this but will again suggest “KISS”. 
 

Chris

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K.I.S.S. solution was provided by Geko, who was the first to reply to Roger B)

On 10/13/2019 at 2:50 PM, Geko said:

You can use a "T" or "Y" brass connector like this. Available at any hardware shop  

WhatsApp Image 2019-10-13 at 21.48.54.jpeg

 

 

Edited by Bfg

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+1

keep the PCV valve 

Edited by Z320

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6 hours ago, Bfg said:

 

Roger,   I respectfully wonder if others are being diverted from the wording of your original post, having taken a fancy to more bling in their engine bay, or otherwise being swayed by thoughts of racing set-ups ..most of which four cylinders are TR2 to TR4 which never had a PCV valve in the first place.?    

The PCV valve is designed to modulate inside crankcase air-pressure slightly lower than ambient air, whatever the altitude (within reason) and throughout the engine-speed range from just ticking over to full chat. The benefits of which I have written of previously. It achieves that surprisingly well considering it's such a simple and reliable device ..as long as it is periodically cleaned out, and the rubber parts (like any on a car) including the pipes are replaced every ten or fifteen years (..more frequently in hot dry climates or with very hard use).  And as has been mentioned previously - it does need to be mounted correctly so its crankcase breather pipe can drain its separated oil  'downhill all the way'  back into the rocker cover. 

So perhaps the question one might ask is "how did others fit a remote brake servo (..and keep their standard PCV valve setup) ?"  

 

In case you do not have a copy, the following references to Triumph's  (optional extra) MOT-A-Vac servo unit, from their workshop manual.  

P1320680.thumb.JPG.0c58a2694fba8f1e9e20cb4a2c770ba2.JPG

And because it was an optional extra that may be fitted retrospectively - the manual includes instructions for fitting the vacuum pipe to the inlet manifold. 

 P1320681.thumb.JPG.78477339e91876ee42b4c475bebf097a.JPG

This workshop manual is really not very good as the TR4A is, at best made, referenced to in supplements,  so the inlet manifold shown (in the photo above) is that of a TR4 rather than 4A. The later car doesn't have the 'cast-on boss'  referred to in this text,  but the 45 degree angle of that seems only to facilitate a more direct route for the vacuum pipe (so that the vacuum pipe doesn't point straight upwards and then kink because of the low bonnet line).  But the principle would be the same ; to drill and tap into the manifold midway across it ..and from that take the pipe (perhaps using a 45 or 90 degree elbow to point it in the right direct) to your remove servo unit.  Or if you don't want to drill and tap a new hole then (as has previously been suggested) simply use a Y or T piece from the breather pipe.   Note., should any part of the vacuum fail  (on the crankcase-breather side or the pipe to your servo) - you would not loose your brakes, only their servo assistance.

For reference here is a photo (courtesy of Jay B from Pennsylvania, on the Triumph Experience forum)  using a rather neat (small) catch tank before the PCV valve. 

02BFF1D9-90E3-4D2C-A738.thumb.jpg.0f2fb90f10c629267ce4d19f7387cdd0.jpg

He claims the catch tank works very well and no oil gets into the PCV valve.  Btw., the nipple on top of the catch tank is a dip stick and not a vent.  It is a closed circuit so the crankcase partial vacuum is maintained. 

Again I hope that helps,  Pete.

 

Hi Pete, thanks that is very interesting, and wow - what an engine bay in JB's car! I Really like the in line catch tank  idea.

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4 hours ago, Z320 said:

Hi Pete,

I'm with you.

Hi Roger,

what are you afraid of?

Ciao, Marco

 

What am I afraid of? Um, trickey.... Spiders? No - quite like them actually, Heights? .........no, not really - love flying including aerobatics, Drowning - sure...but I enjoy scuba diving. Dratts! only thing I can think of is Roller Coasters - just hate them ...... because I am not at the helm!!!

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Interesting to see the installation in the red TR4A...

Have a simillar project in my workshop since years, never finished, lays like lead in the rack.

P1140374-b.JPG.be1e0d12e5c0121c59a7d9140a4a3f99.JPG

I wanted to fit it between the PCV valve and the inlet manifold to see how much oil and dust remains after the PCV valve.

Not worth the effort, the hose is always clean as often I check it. Behind a Mazda 2 lines brake servo to fit the TR4A, another project like lead in the rack.

With this we are back close to the original question :)

Edited by Z320

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13 hours ago, Z320 said:

Interesting to see the installation in the red TR4A...

Have a simillar project in my workshop since years, never finished, lays like lead in the rack.

P1140374-b.JPG.be1e0d12e5c0121c59a7d9140a4a3f99.JPG

I wanted to fit it between the PCV valve and the inlet manifold to see how much oil and dust remains after the PCV valve.

Not worth the effort, the hose is always clean as often I check it. Behind a Mazda 2 lines brake servo to fit the TR4A, another project like lead in the rack.

With this we are back close to the original question :)

Good projects, maybe no oil showing is a sign that your engine is in excellent condition.

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I guess it shows a good working and well adjusted PCV valve.

Had to make some modifications on it to get it work as it should because it is not an original part but a scrap repro part.

These Chinese do not know what we need this part for.

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Thanks everyone for the comments, it's obviously not a clear cut case. I feel keen on a catch tank addition of some sort - and might even put the brake servo on hold, or try an experimental split feed first.

Cheers,

Roger.

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