Across:
8 No romance in South American (no ‘romance’ in ‘South American’= suthia = HIATUS) break (HIATUS),
9 Old partner (EX-) starts temporary experiment (starts ‘temporary experiment’ = -TE-) in Brazil (-RIO-) by writing (from the 3Rs = -R) (EXTERIOR) to Shell (shell/outside = EXTERIOR),
10 Some backward (= reversal indicator) men like (‘men like’ = nlik = KILN) one of those getting fired from the pottery factory (KILN),
11 Immature type (ADOLESCENT) of American (A-) getting unemployment benefit (-DOLE-) near Cologne (-SCENT) (ADOLESCENT),
12 Barman (attorney general = AG-) on holiday (-OUT-) island (-I) (AGOUTI) could be mistaken for a guinea pig (AGOUTI rodent is related to guinea pig),
14 Saves lob (saves lob = ABSOLVES) shot (= anagram indicator) and clears completely (ABSOLVES),
15 They look after the applications (SYSTEMS ANALYSTS) and arrangements (SYSTEMS) for Talking Heads (ANALYSTS) (SYSTEMS ANALYSTS),
18 Mix up (SCRAMBLE) Marcel’s (Marcel’s = SCRAM-LE) production (= anagram indicator) about a follower (‘a’ follower is -B-) (SCRAMBLE),
20 Offers a broad tip to writer (MARKER) who tends to have a defensive approach (football player / MARKER),
22 No one will believe (IT WON’T WASH) one (I-) took gold (WON -) in race (TT race = -T T) and was (WAS-) heckled first (‘heckled’ first = -H) (IT WON’T WASH),
24 Carry on (carry on/manage = COPE) Constable (COP-) – the last movie (the last ‘movie’ = -E) (COPE),
25 Catches (ENSNARES) Egyptian Nubian leaders (‘Egyptian Nubian’ leaders = EN-) unsettling (= anagram indicator) Nasser (Nasser = -SNARES) (ENSNARES),
26 Sailed (sailed = IDEALS) away (= anagram indicator) with models of perfection (IDEALS).
Down:
1 Snapping at (BITING) segment (BIT-) in (-IN-) Government (-G) (BITING),
2 Shock (STUN) of truants missing Art (‘truants’ missing ‘art’ = unts = STUN),
3 Mice pass (mice pass = ESCAPISM) contamination (= anagram indicator) to those living the dream (ESCAPISM),
4 Note (MEMO) concealed by turning over (= reversal indicator) welcome mat (concealed by ‘welcome mat’ = omem = MEMO),
5 Local crazy folk (nutters) losing the head (n) (‘nutters’ without ‘n’ = UTTERS) in States? (states = UTTERS),
6 Lick (lick = -ICKL-) criminal (= anagram indicator) in Bray (Bray = BR-AY-) for expressing hesitation (-ER) (BRICKLAYER) to one of The Masons (mason = BRICKLAYER),
7 Ulster team (DOWN-) find maul (-BEAT) (DOWNBEAT) depressing (DOWNBEAT),
13 The look from the outside in (ULTRASOUND) is particularly reliable? (ultra sound = ULTRASOUND),
14 No stranger to (AWARE) most of (d) the hospital unit (‘ward’ without ‘d’ = -WAR-) in accident and emergency (A-E) (AWARE),
16 Cynthia (Cynthia = YACHTIN-) playing (= anagram indicator) golf (-G) (YACHTING) in overseas competition (YACHTING),
17 A (A-) judge from the past (Resident Magistrate = -RM-) takes over the meeting (the chair = -CHAIR) (ARMCHAIR) – it’s handy when one is sitting (ARMCHAIR),
19 The bloodsuckers (the bloodsuckers = BITERS) responsible for 1 down (BITERS responsible for ‘biting’),
21 Experienced models on both sides (‘experienced models’ on both sides = EXPELS) of bars (EXPELS),
23 Some of the hedge sparrows (some of the ‘hedge sparrows’ = espa) turning up (= reversal indicator) (espa = APSE) in church (APSE),
24 Hands (CREW) to those involved in 16 down (those involved in ‘yachting’ = CREW).